# What causes green spot algae,hair algae and some causes....



## Graeme Edwards

Hi all,

Very quick one.
Could any one tell me the reasons for green spot algae? 
Another one is hair algae, the type thats really quite slimy and looks very soft and almost cloudy when it gathers in big areas. And the last is a tough, almost pubic hair ( sorry if your having your breakfast ) type, deep green algae, often found at the base of rosette plants etc.

I don't get algae in my tanks, but im curious as to why these type are common occurrences in other peoples tanks.

Cheers.


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## George Farmer

Hi Graeme

I don't know if one can link certain attributes to specific algae forms but I can generalise...

Too much light for too long, poor nutrients and underplanting are no.1 cause for newbies.  Tanks don't need high lighting levels to grow plants well, if CO2 and nutrients are appropriate.  Photoperiods don't need to be more than 9 hours.

Assuming CO2 and nutrients are ok, the next culprit is likely lack of circulation.  I've noticed very little GSA, even on slow growers like Anubias when I'm using 10-20x turnover.

Sometimes folk get obsessed with dosing more and more CO2 and nutrients, but without the appropriate vehicle to distribute these nutrients, then it's an uphill battle with algae.

Lack of general maintenance causes algae.  Forgetting to dose, leaving lights on by accident, overfeeding, lack of filter maintenance and substrate maintenance etc. etc.

Another likely culprit, if the algae has suddenly appeared, is lack of water changes especially after big overhauls i.e. re-scapes....  The uprooting of plants with their roots causes nutrients including ammonia to transfer into the water column.  Ammonia/ammonium is a big algae trigger (it's why new tanks often go through early algae issues).

After any in-tank maintenance I will always follow with a water change, concentrating of siphoning any floating debris.


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## hellohefalump

I used to have a medium sized problem with green spot algae.  I put an extra powerhead in, making my turnover about 10X, and it's got A LOT better.  Now I only have a very small amount of it.

I'm currently battling hair algae.  It started when I went on holiday and my CO2 decided to go haywire (still have no idea why) and killed some fish.  I think the fluctuating levels triggered it.  But weeks later... I'm still getting it.  I think I know why.  Yesterday I cleaned my filters out.  Recently I've been a bit lazy with cleaning them and they were really dirty.  I'm hoping now they're clean, the hair algae will start to recede.


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## Graeme Edwards

Thanks George mate.....

I know all that, but i thought there might of been poticular triggers. Like for spot aglae being down to low phosphats?
I never have any problems on my own tanks, but have found with working at TGM there are many people who do, so its nice to hear how and why people get it and the relivant remedies that work, apart from better maintainance, flow, water changes etc.

Cheers.


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## ceg4048

Actually, one can in fact attribute major causal factors to various types. All one needs do is review JamesC's or Dusko's websites to see a list of each. GSA is predominantly a PO4/CO2 related algae and hair is predominantly a CO2 related one. While lighting levels and circulation are important contributory factors, and should be addressed as George points out, the actual mechanism of failure is associated with the specific shortage of these nutrients. I agree with George's assessment that there is a tunnel vision focused only on nutrient levels without proper thought given to their distribution and delivery of the nutrients as well as misconceptions regarding the strongest factor which is light energy input.

Cheers,


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## Brenmuk

In the past I have had on going problems with algae, especially hair algae but it was at manageable levels until I added some sea shells to the tank for decorations. My tap water was already moderately hard with a ph of 7.0 - 7.5 but soon after the addition of the shells the hair algae went into overdrive and the plants declined. 
From what I have read many types of algae seem to do allot better at higher ph and hardness than acquatic plants.
I suppose adding CO2 would alleviate the problem or in my case just removing the shells and other sources of additional hardness.


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## ceg4048

There is actually very little demonstrated correlation between water hardness/pH and algal proliferation. You'll find just as much algae, hair or otherwise, in softwater low pH tanks as in hardwater higher pH tanks. You'll also find just as much poor growth in either type of tank. Something _else_ happened or you did something else in your tank to drive higher algal growth other than just the addition of shells. You did something that you were unaware of, or that had a secondary effect of either lowering the CO2 content/stability, adversely affecting flow or distribution, or increasing the available light energy. The shell addition was a bystander and was blamed due to circumstantial evidence. Hair is fundamentally coupled to a light-CO2 uptake equation. pH has nothing to do with it.

Cheers,


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## Brenmuk

Your probably right. Its just my experience that when I added shells to my tank battling algae became alot harder. Also when I set up a tanganikan shell dweller tank with lots of sea shells and tufa rock it was almost impossible to grow plants (I used java moss, java fern and anubias nana) - i think i got the ph up to around 8.5.
Although looking back I could have tried some vallis and some floating plants.
Surely very high ph/alkalinity would convert all the available CO2 into CO3 thus favouring CO3 prefering algae?


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## ceg4048

Well, there are plenty of CO3/HCO3 using plants as well such as Vallis, Crinum or even some of the Hygrophylas I think. The plants you used in the Tanganyikan, although necessary for fish compatibility are very slow growing so are not the best to use in testing this theory. Rift valley tank are difficult because it's much more difficult to reconcile the plant needs with the fish behavior but very few pep[le actually test the alkaline water theory by simply eliminating the fish and seeing what is possible. The fish are always present so no one in their right mind will play around to test ultimate limits of plants while the fish are in residence.

In more typical tanks, one reason people find it difficult is precisely because they focus on alkalinity instead of on CO2. It's entirely possible for example that the plant biomass increased beyond the amount of CO2 that you were adding. Increased biomass means increased demand for CO2. Increased biomass also means increased blockage and interference from leaf to leaf thereby reducing the available CO2 to each leaf.

It's CO3/HCO3 utilization is not really a preferred uptake mechanism. It's more like a more expensive auxiliary uptake mechanism. The reason is that only CO2 can be used in the carbon assimilation system of which higher plants and algae are constructed. This mechanism is referred to as The Calvin Cycle, or The Dark Reaction, or the more pedestrian Photosystem 1. HCO3 has to be reduce to CO2 by certain enzymes before being sent to the assimilation reaction chambers. The more direct the CO2 availability the more effective photosynthesis is.

While so many focus on alkalinity in the water column they miss the big picture of carbon assimilation. All roads in plant physiology must lead ultimately to CO2. In a way, that's why plants were created, to process CO2 and to turn it into fruits and vegetables. Carbon assimilation failure in plants is akin to core meltdown in a nuclear powerplant. This is the reason we have so much algae in the hobby, because attention is diverted away from CO2 and instead onto pH or alkalinity which have much less relevance.

Cheers,


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## scottturnbull

My own hunch - and this _is_ just a hunch - is that when plant tissues are weakened, a localised micro-climate of _different_ microorganisms, either feasting on decaying material, or feasting on each other, builds up around the tissues, creating a soup of microorganisms and organic by-products. Algae can survive in this environment better, because it can withstand a loss of cells, without being compromised. Cell damage in higher plants, on the other hand, compromises tissues and organs. Resources need to be diverted from healthy tissues, weakening the whole organism. This is consistent with the observations people make about increased circulation, and CO2, preventing algae. Circulation would disperse the micro-climate, effectively diluting it, allowing healthier plants to share the burden of resistance. Supplemental CO2 and Nutrients - if provided carefully - will increase the resistance further, and reduce the likelihood of weaknesses appearing in the first place.

Like I say, it's just an unscientific hunch based on looking at tissues and algal filaments under a microscope, and witnessing _increased_ bacterial and protozoa activity, versus healthy tissues. I'm not a phycologist.


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## ceg4048

Well, there is always a biofilm surrounding and attached to the plant external tissues. This is called the periphytic layer and it covers all wetted surfaces, organic or inorganic. It's existence is inevitable. The surface of the leaf membrane is enclosed with a hydrocarbon layer called the cuticular membrane (CM). This cuticle originates from the waxy coating that terrestrial plants have which prevents water loss in air. In aquatic macrophytes this cuticle very much thinner but serves to protect the plant tissue from attack by the organisms in the periphyton, including resistance to algal attachment. The hydrocarbon material is by definition made up of long carbon chain molecules. Poor CO2 degrades the carbon content of the plant globally causing breakdown of the hydrocarbon based cuticular membrane (as well as decay as you mention) allowing organisms within the periphyton to attack. This also allows unimpeded leaching of nutrients and ammonia from the plant. Algal spores can then bloom as they are in the periphyton and have direct access to ammonia and light as well as nutrients. Hair, Staghorn and BBA spores which are always present seem to be the quickest to attack when there is carbon failure.

The reason flow is important is because it is extremely difficult for CO2 to diffuse across the CM. There is also a region called the boundary layer which is essentially stagnant water just next to the leaf surface. So there are two serious obstacles to CO2 ingestion. The ability of CO2 to diffuse through water is about 10,000X less than in air so it is very important to lower the thickness of this boundary layer. Hydrodynamically, higher flow has a significant effect in reducing the thickness of the boundary layer. To overcome the poor diffusion property of water a higher CO2 gradient is required. So high CO2 concentration in the water column allows osmotic forces to push CO2 across these obstacles and higher flow reduces the height of the obstacle across which the CO2 must then cross.

Cheers,


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## scottturnbull

I've added some italics to my previous post to save you the effort of having to read it carefully.


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## ceg4048

I don't see where the italics helped to clarify. It might have been better for you to specifically state, in a different way, what it is you are trying to emphasize. Plants are impervious to microbial activity within the biofilm whether different or same. Damaged tissue does not automatically mean algae. If that were the case, every time you cut a plant via pruning you would get algae at the site of the cut. I can inflict a lot of mechanical damage without ever seeing algae at the damage site  or at any other site on the plant, even though the tissue at the cut site browns and decays. We see this every day therefore microbial activity at localized sites cannot be a significant causal factor. However, decay of the plants basic infrastructure, such as cell wall collapse, loss of enzyme or membrane production due to nutrient starvation does make the plant more susceptible to direct algal attacks without any moderating effects of other members of the microbial community. 

As I tried to explain, the effect of localized decaying material has the effect of producing localized high NH4 concentration and that, in the presence of light does trigger the bloom of algal spores. If the plant is further weakened by nutrient/CO2 starvation due to poor flow then the algae are able to more easily attach to the substructure. It is not a matter of algae being able to survive in localized micro-climate of different micro-organisms. The plants do just as well from that point of view. 

Review more carefully my explanation of the effects of hydrodynamics and diffusion limitations, within the context of this clarification and see if it makes any more sense and forget about the microorganism hunch because there are many more organisms in that micro-climate that actually _help_ the plants battle against algae and that the plants directly support via symbiosis than nasty ones.

Cheers,


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## scottturnbull

You disagree. That's fine with me. You have your own theories. I respect them. I can see merit in some of them.

I'm talking about increased numbers of micro-organisms (bacteria and protozoa etc.) as well as different types which aren't usually present in great numbers. Since it was a hunch, and this is an internet forum, I forwent the usual terse language, partly to make it easier for people to understand, and partly because I assume most people here are aware that bacteria exist even in a healthy aquarium (which you pointed out, with your usual amount of humility).

It's difficult to swallow the argument that microorganisms don't play any role whatsoever. A lot of them produce ammonia. Ammonia is a signature in an unbalanced aquarium. Like I say, I'm not an expert. Maybe you are. I have my doubts about that, but I could be wrong.

I'm not particularly attached to my hunch. If I find a better explanation, I'll jettison it. I'm suspicious of inductive arguments. I won't be doing back-flips trying to prove my hunch in the face of contrary data, should someone present a compelling alternative. I'm open to ideas.

I'll leave it at that for now.

Take care.


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## ceg4048

scottturnbull said:
			
		

> ...It's difficult to swallow the argument that microorganisms don't play any role whatsoever. A lot of them produce ammonia. Ammonia is a signature in an unbalanced aquarium..."


Yep this I totally agree with, is more lucid than what was stated or italicized before. I certainly wouldn't imply that microorganisms don't play a role. What I'm arguing is that there is little impact of direct tissue attack against the plant by the protozoan community, which is what it seemed you were saying. As you say, some produce ammonia, and some oxidize ammonia as well. The net impact can be localized ammonia concentration rise. These micro-organisms are attached via the biofilm and while flow may have little effect on their population, flow does remove the loose particles as well as the ammonia. If your post was meant to say something along this line then we were actually in agreement and I do most humbly apologize. As you've surmise, I'm no expert but I merely pay attention to what real experts have to say and then implement what is learned.

What one needs to be able to do though is strongly correlate a suspected causal factor, in this case CO2 with an algae type such as hair. Try lowering the CO2 for a few weeks and then raising it.  You'll find that you can induce hair/staghorn/BBA easily by lowering the CO2. You can then eliminate it by the reverse and this can be observed consistently. Similarly, GSA can be induced by lowering the PO4 and can then be reversed by increasing the levels. Following expert advice I've done this enough times (both intentionally and unintentionally) to observe a strong correlation. There are sure to be other contributory factors but these are clearly the strongest.

Cheers,


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## Graeme Edwards

Why should simply raising Co2 ppm have such a huge impact on the production of algae or lack of? Is it down to plant growth - plants start growing harder, so thus out compete with the algae? Is it as simple as that? What if you crank your Co2 up, but have a low bio mass. Are you not worried about fish at this point.Where do you draw the line. Are we looking at fish health, grow rate, flow rate, lighting and biomass all at one point to asses what the required action should be? I say yes.

Im simply asking the questions that many wish to know.

Interesting points about trimming plants and open cuts, it all makes good sense to me.


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## plantbrain

Graeme Edwards said:
			
		

> Why should simply raising Co2 ppm have such a huge impact on the production of algae or lack of? Is it down to plant growth - plants start growing harder, so thus out compete with the algae? Is it as simple as that? What if you crank your Co2 up, but have a low bio mass. Are you not worried about fish at this point.Where do you draw the line. Are we looking at fish health, grow rate, flow rate, lighting and biomass all at one point to asses what the required action should be? I say yes.
> 
> Im simply asking the questions that many wish to know.
> 
> Interesting points about trimming plants and open cuts, it all makes good sense to me.




Oooo, OOOooo! I know this one  

1. Do you see algae on new tips or older leaves?
Older, takes time for bacteria and algae to colonize.
Fast growing weeds= less algae as you can trim the tops and toss the lower infested parts.
Also, as new growth fills in, the algae gets shadowed(less light).
Less light = less CO2 demand and less algae growth, because algae are not CO2 limited to begin with........

CO2 variation makes for a good signal when to grow for an algae spore, means there's a large shift/change in the system (some is rotting and releasing nutrients, decaying etc, and or something is not using up the CO2 like before).
Both good seasonal change signals.

But plants need huge amounts of Carbon to grow, algae simply need very little.
If you limit CO2 and have high light, plants slow or stop growng, they get progressively smaller tips. Now they are pretty much like rocks and driftwood, just substrate for algae to grow on.

It takes time for the plants to retool their metabolism and get going again once they have been limited. They wait and will start new growth again after some time of good stable conditions. The old growth is general sacrificed(they are fast growing weeds and go up to the surface and block light below to gain the upper hand).
Algae have no issues with retooling because they are small single cell and have no limitations.
NH4 is one item that seems to induce algae, but CO2 seems a larger reason.

These are the only 2 chemical parameters I know of and can confirm.
But.......this is not all about chemicals...........there's light involved here and few folks bother to measure it for comparison. This maybe changing soon.

Other issues are indirect: "I forgot to clean the filter and it reduced flow way down and has loads of flith and organic matter........" I did not top off my aquarium due to evaporation loss and the flow degassed a lot of the CO2".........I assumed my CO2 was fine based on a test kit/method"

These are human social issues..........that often are over looked. Folks get tunnel vision with nutrients.
Better to focus on CO2 and hedge your bets with low light, good general care, current, water changes, pruning, adding ferts to both the water column and the sediment etc.

This makes errors much less and takes off demand on nutrients/CO2.
Growth is slower, but the likelyhood of alga is greatly reduced.

Plants can and do respond to changes in our aquariums, and in nature, but generally they are much slower lumbering beast. Takes them awhile to gear up with enzymes(Rubsico particularly- it's the wolrds most common enzyme and the largest one in aquatic plants), transportation within the plant, allocation of resources to where they need to be.
This takes time, and algae have no such issues, they do not need to make large carbon based stems, leaves etc.
Plants do and at a much higher demand and have a much lower surface to volume ratio than algae(makes uptake harder).

Algae are also generally fleeting..........they do their thing and produce spores having completed the asexual/sexual spore lifecycle/s. Sort of like annuals(algae) vs perennials(plants) ecology.

Also, healthy strong plant growth = lots of O2= lots of good fast cycling by bacteria, as well as good uptake by plants. These guys work togeher, when you stop plant growth, you stop adding the O2, the sediment "dies", roots stop pumping O2 down there, the bacterial colonies slow and whither............You can do this easily by reducing/limiting CO2.
These are secondary effects, but play roles in algae it would seem to me.
Good sediment establishment and health plays a large role I think.

It's not just bacteria however, it's a complex of roots and plant health, as well as waste loading from fish, shrimp, plant decay, driftwood, detritus, tannins, and...........bacteria and other tiny microsopic critters/inverts. If this is short circuited..........then things fall apart and take time to reestablish.

Small changes are less of an issue, large uprooting without care/water changes often lead to algae.
Stopping plant growth by 10-20X correlates into 10-20X less root growth and O2 production.
Aquatic plant tank sediments are pretty aerobic mostly, this is due to the plants' roots.
In natural systems, they do not like a lot organic matter which causes low REdox levels, if you stop growing roots/producing O2, those redox levels become worse for plants(they become more negative), and adding more OM(organic matter) reduces it even more as roots rot from lack of O2 etc. They need some OM to help cycling and bacteria need their carbs just like us....but not too much, nor too little.

10% to perhaps 1% is good for OM.
Reduced carbon is the heart of all things sediment and bacterial.
Once you realize this and how plant roots behave, all the heating cables, power sand talk makes little sense. That's Engineering talk and yammering, not botanty or plant biological talk. Microbiology is part of this as well, but not quite as much as some think and a lot more than others think.

Tropica raises their plants in sterile hydroponics culture, no CO2 issues(air gas phase sources), so no light , CO2 or nutrient limitation issues nor bacteria.

Fine for plant production, but not for fish, we want water
A side note is that 90-95% of all nursery container plants are grown pretty much the same way as hydoponics using fertigation water, and soiless media in the pots(generally bark and sand for weight and to hold the roots).


Regards, 
Tom Barr


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## ceg4048

Well, Tom's said it all and I think you've hit the nail on the head when you mention plant growth. Almost half of the plant's dry weight is carbon. It's hard to find an enzyme or a protein or any complex molecule that isn't formed from a carbon structure. In a way, the study of biochemistry is the study of carbon and it's bewildering array and complexity of compounds. Think about the word "Carbohydrate" for a second.  The "Carbo" means Carbon. 

Have you ever heard of the "Atkins Diet"? One reason for it's effectiveness is that it eliminates any form of carbohydrates from the diet. No starch, nor sugar. So the only carbon in the diet is what your body gets from breaking down the proteins in meat and veg and fats, which is less efficient. Living cells are powered by burning carbohydrates, principally glucose. And this is what plants produce as a direct result of photosynthesis,  a phosphate-carbohydrate which is then turned into glucose.

When you starve the plants of CO2 you are basically placing them on a an Atkins diet and they have to then start cannibalizing themselves just to keep going. Just to keep their cells fed. That means their basic structure as well as enzymes and proteins that ought to be used for growth processes have to be broken down and the carbon from these components scavenged to to keep the remaining cells alive. This is a double whammy because photosynthesis (and therefore food production) grinds to a halt due to loss of enzymes that power the process, and whatever glucose reserves have been built up get used during the emergency and are not replaced. So it's even more serious than an Atkins diet, it's an ethnic cleansing concentration camp diet.

So this is why mild carbon starvation generates those organic products that leech out and scum the surface. Why moderate-severe carbon starvation results in algal attacks and why acute carbon starvation results in discolouration, browning, holes and other tissue loss such as disintegration and leaf loss. Any kind of tissue loss in a plant should immediately rouse suspicion of carbon loss because that means cannibalization and the inability to replace the tissue structure.

Not only do we need high CO2 concentration but the famous stability issue is also important. The plant senses the concentration in the water column by using the holes or stomata on the lower side of the leaf. This quantity is then used to command the production of Rubisco which is probably THE most important enzyme. The Rubisco production is tailored specifically to the sensed level of CO2 in the water column. Rubisco's job is to attach itself to a CO2 molecule and another molecule the plant recycles (called RuBP). The Rubisco then transports these two molecules to the photosynthesis reaction chambers of the chloroplasts where the carbon is stripped. 

But there are a couple of really big problems:
Problem 1: Rubisco is itself a HUGE carbon molecule and takes a long time to produce.
When the plant decides to increase Rubisco production it now has to allocate more carbon and more nutrients to this enzyme's production which leaves less available carbon to feed other systems of the growing plant. If the amount of CO2 in the water column falls lower than what was sensed prior then Rubisco production was wasted because it cannot use more Rubisco than available CO2. The result is waste and slowed growth. Then suppose the mean CO2 levels increases again? The cycle of commanded increased Rubisco production begins again. Each time there is a cycle of rises and fall of CO2 concentration the plant becomes weaker and weaker as it diverts resources to Rubisco production that it didn't need to do and consumes more carbon than it could afford to do which can result in structural failure as in the case of simple low CO2 levels.

Problem 2: Rubisco is just as easily attracted to oxygen (O2)as it is to CO2.
If the CO2 concentration level is low relative to the O2 levels Rubisco attaches to O2 molecules which are useless in the photosynthesis reaction chamber (Calvin Cycle) which lowers food production further weakening the plant.

As you can see, there is a massive impact to carbon starvation - much more than people realize. I've already talked about how difficult it is to actually get CO2 across the waxy cuticle from the water column and into the cytoplasm, and these problems are only exacerbated by poor flow and/or poor injection techniques - not to mention high light which serves to commands a higher Rubisco production as well. This is why I'm such a CO2 fanatic.

At the end of the day though, as you say Graeme, is that we must find a balance between fish and plant health. We can mitigate the problems of CO2 toxicity by having even and adequate flow to allow the plants to make better use of the CO2 levels that are available. We can alleviate the situation by keeping plants that are very capable of using HCO3 such as Vallis. We can strive to avoid too much of a jungle scape that tends to block flow (or if we do have a jungle we can trim more often). A more open grassland type or simple mound type scape goes a long way there. We can supplement the CO2 levels by dosing Excel and most importantly we can lower the Rubisco and CO2 demand by avoiding massive lighting levels.

Cheers,


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## Graeme Edwards

Nice  8)  And in normal man speak to, thanks.

I know growing plants and not growing algae is not as complicated as it may seem,but so many people make it complicated. You have answered that question well, and it has not gone above me, which is often the case when chemical talk, NHO3 etc etc starts turning up. Im an artist, not a chemist or biologist. All I want to know is how to grow plants well so I can create, and do this in the easiest and least complicated way. Im sure I am not the only one.

Cheers all for the contributions to this post.  8)


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## keymaker

ceg4048 said:
			
		

> Hair, Staghorn and BBA spores which are always present seem to be the quickest to attack when there is carbon failure.


As you probably read on my blog, I've been fighting Staghorn algae for at least 6 months now. You know that I share Tom Barr's and Clive's views on algae blooming triggers. I fully accept there must be some kind of CO2 issue in my nano tank, but I am not able to find the practical cause. Please help me find it.







Please note that I'm familiar with such issues as higher CO2 demand during the beginning of the photosynthesis period and the importance of CO2 stability during the photo period and long-term consistency and the whole carbon-fixation procedure. I'm familiar with the injection + flow (CO2 delivery) theory.

In short: I'm not looking for a theoretical answer. What I'm looking for is a "clear-headed" look at the current situation and help to find if I'm missing something in this case. Just like a debug in the Matrix. 

Please also note that due to the experimental purpose of this tank I do not intend to decrease the lighting, and to comply with my daily schedule I need the lights to stay on until 11PM. 






*Facts:* 

- It is a high light (5.4 WPG) tank with pressurized CO2 addition.
- Bubble rate is stable and really high (150 bpm), experience has shown that any more would cause fish gasping.
- The flow is really good (25x with filter max flow data and 17x with filter load max flow data, the actual is around 10x)
- The surface movement looks optimal (good surface movement but without breaking the surface).
- The glass CO2 diffuser is producing really heavy bubbling - just like an airstone - this might contribute to the loss of CO2 with surface movement.
- Drop checker is lime green towards yellow in all areas of the fishtank.
- The solenoid valve switches CO2 injection on at 11:30 AM (drop checker green), half of the lights switch on at 13:30 (drop checker light green), the other half switches on at 14:30.
- CO2 switches off at 10PM, lights at 11PM.
- No direct sunlight on the tank.
- There is some morning light on the tank until CO2 switches on.
- Most of the injected CO2 is lost during the night because of the surface movement. The drop checker indicates about 15-20 ppm CO2 in the morning hours (this measurement is accurate by my experience!).
- Plant fertilizing: overdosed (!) TPN+ with complementary Potassium Sulphate as well as Potassium Phosphate addition. All values stable and above the EI range.
- Plant fertilizing history: I had a problem with the low K and PO4 levels in TPN+. This lead to HC troubles, the staghorn appeared on the plants that suffered. I'm certain that Ammonia was the primary trigger. Growth is good now, but with HC it is difficult to get rid of the old affected leaves without uprooting the whole carpet. I tried to dose Easy Carbo directly over the leaves, that caused some of the staghorn to redden but it did not get rid of it...

*My view of the facts:*
The CO2 level during the "lights-on" period is constant, properly distributed and sufficient to provide for the high-light requirements. Plants do not suffer nutrient deficiencies.

In this particular case the Staghorn Algae presence is caused by CO2 fluctuation issues not by CO2 insufficiency. The algae is also present on the rocks where the bubbles and the CO2 rich water is touching the ground.







*Questions:*

- Can the morning indirect lights cause carbon failure with the plants? The period in question is the time between 8AM-11:30AM. The light is not very strong as the tank is far away from the windows, but enough to read a book without problems.
- Can switching the CO2 off one hour before lights cause any trouble?
- What should I do with the staghorn affected HC? Should I uproot it all or should I just try to get rid of some of the algae (the bigger ones) and wait for it to disappear?
- Am I missing something here? What would you change in the injection regime?






Thanks for reading this and thanks for taking the time to consider this situation!  :idea:


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## Ed Seeley

Three things spring to mind that I don't think you mentioned:

1. Is there any flow directed down at the problem areas?  As this is on the substrate could it be that the circulation is not optimal down there?  What I'm thinking if if your external (I assume?) has a lily pipe on then most of the flow may well be spinning around off the bottom of the tank allowing fluctuating CO2 at/near the base.

2. Do you have any shrimp or SAEs in there?  Maybe a decent crew of shrimp will eat the algae, or at least slow it down.  SAEs might also eat this if I remember rightly?  Could tip the balance in your favour for a while.

3.  You said the EasyCarbo caused it to redden.  Did you stop dosing it?  Maybe it might be worth trying that again at double dosage squirted straight at the algae filled areas?


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## keymaker

Ed Seeley said:
			
		

> 1. Is there any flow directed down at the problem areas?  As this is on the substrate could it be that the circulation is not optimal down there?  What I'm thinking if if your external (I assume?) has a lily pipe on then most of the flow may well be spinning around off the bottom of the tank allowing fluctuating CO2 at/near the base.


The CO2 enriched flow from the lily pipe goes directly to- and along the bottom so there is optimal circulation. In a small tank like this and a high filter turnover flow should not be an issue.



			
				Ed Seeley said:
			
		

> 2. Do you have any shrimp or SAEs in there?  Maybe a decent crew of shrimp will eat the algae, or at least slow it down.  SAEs might also eat this if I remember rightly?  Could tip the balance in your favour for a while.


Yes, I forgot to mention. There are 4 Red Cherry shrip, 4 Amano, 4 Otos, and 1 SAE in the tank. But I'm looking to solve the main reason of the algae, not to get rid of it with fish/inverts - so to speak.



			
				Ed Seeley said:
			
		

> 3.  You said the EasyCarbo caused it to redden.  Did you stop dosing it?  Maybe it might be worth trying that again at double dosage squirted straight at the algae filled areas?


I still dose Easy Carbo at a heavy rate 1ml/20l/day. Any more than this and shrimp would suffer. I had lost one when I tried to up that value.

Ed, thanks for your answer. If you have any more ideas, please post them.

Cheers.


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## ceg4048

Hi Balazs,
              Can we see an image of how your flow pipework is configured? it's no good hammering the plants with flow as this can sometimes do more harm than good. Also, you need to consider that algae like CO2 as well so you might have induced it, made the proper changes but were still feeding it. You have to get rid of the stuff that's there and then carry on. The question is did the staghorn emerge with this present configuration or had you been changing the configuration of bubble rates, pipework, dosing etc when it appeared? I suggest the 3 day blackout + water changes daily + Excel dosing routine to clean the slate. If your current configuration is valid then the algae should not return. Definitely cut out sections and remove as much as you can. If that means temporarily wrecking the scape then so be it.

I don't think the indirect lighting is the culprit here. My tank sits in a conservatory which means it's basically outdoors with almost full sunlight so this can't be too much of an issue. The OFF time for CO2 is much less important than the ON time so that's not an issue.

You must also consider the possibility that the requirements of your fauna are at odds with the requirement of the plants under such massive lighting conditions. Having said that though Barr describes staghorn as a transient species, i.e. one which is stimulated by changing conditions in the tank (rescape, overfeeding and so forth). Once conditions are stabilized it normally goes away, however the strong lighting doesn't help so you may want to carefully increase the lighting after the blackout.

Cheers,


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## keymaker

Clive, thx for your answer!



			
				ceg4048 said:
			
		

> Can we see an image of how your flow pipework is configured? it's no good hammering the plants with flow as this can sometimes do more harm than good.


I uploaded a video of the tank, hope this shows the situation better. The inflow is on the left, the outfow is on the right. The flow pushes the CO2 bubbles on the left side of the tank towards the ground and then to the right...





			
				ceg4048 said:
			
		

> The question is did the staghorn emerge with this present configuration or had you been changing the configuration of bubble rates, pipework, dosing etc when it appeared?


The cause of the appearance is clear: not enough K and PO4 in the TPN+ which lead to plant deficiency. As soon as I realized that and started adding K2SO4 and KH2PO4 the growth is back on track. There were no other changes.



			
				ceg4048 said:
			
		

> Definitely cut out sections and remove as much as you can. If that means temporarily wrecking the scape then so be it.


I will definitely replant the whole HC carpet once the tank is fully matured (and the diatoms are gone). It is impossible to cut out sections of the HC. All of it is affected. Until then there's no point in making a BO.


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