• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Beginning of algaes after doubling light

CO2 is generally highest at the top because that's where it is escaping. That's one of the reasons carpet plants are notoriously difficult, because they are at the bottom where flow, distribution and gas levels are typically poorest.

The best that we can do without a direct meter is to use the values we measure as a proxy for the other locations, recognizing that there are no absolute values and that we are getting only a general number.

If your fish are suffering hypercapnia then you need to look more closely at the flow/distribution or timing, which are always suspect, especially as the plant mass increases. You can turn the gas off earlier as only the first few half of the photoperiod are critical for CO2.

Cheers,
 
Thanks Ceg!

My pH profile: -
15958858408_26749127c2.jpgpH profile 29-12 by pepedopolous, on Flickr

I can turn off the CO2 earlier but I think I might have relatively high degassing as you can see from the graph when the CO2 goes off. The fish were at the surface from as early as 16:00.
You notice that I 'only' have a drop of just over 1 pH unit and that the pH is pretty much stable, so I was surprised to see the unhappy fish. KH = 4.
I thought that this might be explained by the fact that in general the CO2 might be higher lower down in the water column than where I put the pH meter.
Anyway, I've actually lowered the CO2 bubble count to keep the fish happy. I'll have to see if the plants respond negatively...

P
 
Ok, that can work as well. There are a few ways to skin the cat. It's also possible to increase the rate and reduce the injection period (or start earlier), so either can work.

Cheers,
 
Clive (ceg4048), please, can you explain me in more detail what factor am I not taking into account in saying that 15-20 ppm CO2 should be enough for growing most of our aquatic plants?

Also, you can believe that high light and low CO2 induce algae, but without any solid data it's only your belief. So if you have any data, please share them with us. I would be the first to change my opinion, and admit I (and many scientists) was wrong.

When you speak about high uptake, according to many scientific papers (which EI people don't like to read), for majority of aquatic plants the CO2 saturation point at full sunlight (1500-2000 µmol PAR), and non-limiting nutrients (Hoagland's solution) is 0.5 to 1.0 mM = 22-44 ppm (mg/L). As you probably know, at lower light levels (50-400 µmol PAR in our tanks) the nutrient uptake rate would be much, much slower! So if at non-limiting conditions the majority of aquatic plants are able to uptake 20-40 ppm CO2 at most, then at light limiting conditions the 15-20 ppm CO2 could be their maximum they can uptake (at these lower light levels). I don't know how to say it more clearly.

Also, when you speak of different conditions in different parts of our tanks, then when you recommend some CO2 values to other people, why don't you tell them what part of the tank your recommendation is meant for? If at plant beds the pH/CO2 values are so dramatically lower then in the middle of the tank, then where this 35 ppm (or 50 ppm) is meant to be?

As to the algae, and low pH causing their inhibition or even death, it's very easy to say, "This is not true at all", without giving us any solid data again. I have some scientific papers which say that each algae species has some pH tolerance range, and for Audouinella species (BBA) this range is somewhere around pH 6.5 to 8.5, and that some cyanobacteria species are greatly inhibited at pH 6.5, and at pH 6 or lower they just die off. If you say it's a nonsense, then please give me some other data. Or did you test different algae species in a closed system (eliminating all other factors) at different pH yourself? Again, why don't you share your data with us? To base our belief on our experience only can be misleading, as our own observations can lead us to wrong conclusions. Often we overlook some important factors, unlike many scientists. For example, you belief that high levels of nutrient don't pose any risk as to the algae, but at the same time you seem to overlook many inhibitory factors which may play a role at your tank in this regard. So if you have a loads of nutrients and high light in your tank, but at the same time you have many algae-eaters (algivores), you do regular water changes, have a good filtration, and don't give your algae any time to develop, but each week you reset their environment ... then at these conditions and inhibitory factors, you may have no problem with algae. But this doesn't proove that high nutrient level pose no risk, or that high nutrient level + high light don't lead to algae. No! This means and proves just nothing more then you have some factors in your tank which suppress algae or prevent them from developing. Remove these factors, and leave only high nutrient levels + high light there ... and see what happens.

So if I fundamentally misinterpret the facts and data, please, can you show me the correct data? I do my best to find out some correct data on these topics at ScienceDirect, Scopus, ProQuest, Whiley and other databases. So I would welcome if you can give me some links to relevant articles or research results.

Marcel
 
Last edited by a moderator:
Just some comments from an EI-using hobbyist- not a scientist.

I think Ardjuna has a point about water changes. Both EI (high nutrient) and ADA (low nutrient) methods require weekly 50% water changes which must remove a lot of nutrients/waste, and algae/spores. I know that EI proponents state that the water change is needed to remove 'plant waste products' but what are these products? Wouldn't these be quickly broken down into basically the same nutrients that we add as fertiliser (nitrates...) ? Isn't this contradicting the very idea that nutrients don't cause algae?

OK, perhaps it is ammonia that builds up first but 1) plant's as well as algae can use ammonia as a nutrient, 2) at low pH (<8) free ammonia isn't so toxic right? I know Ceg talks about ammonia signalling dormant 'predator' algae to 'wake up' so perhaps that is the point... 😕

Secondly, Tom Barr uses Wet/Dry filters with surface-skimming overflows, even though they cause a lot of degassing. ADA recommend aeration overnight. Degassing seem to be really important for stable CO2 and O2 yet how many hobbyists actually use a Wet/Dry filter, air stones or even raise their filter outlets at night as recommended by ADA? As water evaporates and the water level drops, surface disturbance from lily pipes/spraybars increases so many aquariums must be inconsistent in this aspect which will have an effect on CO2 levels.

I'm not a scientist but I know that only science can explain the successes and failures we have. There is no authority in science, just hypotheses and data which support or doesn't support them. In our hobby we have plenty of hobbyist hypotheses but next to no data from controlled experiments where only one variable is examined at a time. Anyway, let's keep this scientific and not personal. 🙂

P
 
I don't believe ammonia itself or ammonia spikes are responsible for algae infestations. Even T.Barr doesn't believe it anymore:
"I suggested some years ago that NH4 was a cause for GW blooms, and other algae perhaps. This seems false, but the increasing fish loading sure seems to cause algae in every test I've done or seen."
Click to expand...
=> see the first post here. Plants are able to remove ammonia very quickly from the water, as they prefer NH4 before NO3. Also me and my friend, we both have 0.2 to 0.3 ppm NH4 in our tank water (= laboratory analysis), and we don't have any algae problems. And beside this, according to algologists most algae in natural water as well as in aquariums are in vegetative state, and not in the form of spores (in dormant state) as some people try to convince us. I analyzed water samples from different tanks many times, and we never found any algae spores ... but we always found many algae cells. What does it mean? That all kinds of algae are already present in our tanks as vegetative cells, just waiting for some coincidence of conditions (enough nutrients, light, time ... no inhibiting factors) to grow.
 
I'd like to suggest that doing something such as doubling light intensity or period is always likely to lead to troubles because you're then asking the plants to make an immediate massive adjustment to conditions. If this hobby teaches us anything then perhaps firstly it should be patience because plants respond so slowly to changes so always make slow gradual changes like increasing light very gradually over a week to 10 days.

Could it be that CO2 levels etc. were already very close to what was required but that the added light was simply too much stress for the plants to adapt to quickly enough and so the algae cried whoopeeee?
 
Good morning,
Well, i read all your coments. I think this Co2 issue will never end..
This is what i´m going to do:


I have the Co2 drop cheker coming to a green/yellow only by the end of the day (wich i suposed to be the readings for a couple of hours before as the reagent is not instantaneous).
So I think it´s not enough but ím almost at the point. I think we should get this level (colour of the drop) at list around half of the photoperiod. My lights turn on at 14 hours so i should get that colour at list around 18 hours Pm. Four hours after wich corresponds to the readings of two before.
Now, as we are in the weekend, this morning i increase a bit the co2. Just a little little bit. A single touch in the valve.
By the time i got home i´m going to check the fish. If they are "swimming" at the top of the water then i know i had it right before (wich i doubt). If they doesn´t i´m going to increase a little bit more. And Saturday by the end of the day check again the fish. Repeating this procedure till i find them in the top of the water looking for 02
By this procedure i will achive maximum level of co2 i can inject. This should give a unique yellow colour in the drop. No signs of green what so ever.
By the time this happen i should reduce what i´ve increased before in the morning cause i overcross the maximum level right? But still in this point i´m at the maximum cause i only reduce what i´ve increased in the morning wich is the excess.
So i will reduce (returning the valve) the same amount corresponding the two days before wich is near the maximum level but not max. it´s almost there. And then check the colour of the drop. If it´s still total yellow than i know i can decrease a bit more. But that is a matter of choice and risk.
As we can´t get an understanding on Co2 and i´m on this fight for quite a long time now, .. I´m going to take the cance, prefer being near the maximum level because by this way i know there will never be less co2 in the tank. I´m giving the most i can.

Do you understand ? Confusing? It´s quite simple, but i don´t know if i write it right to you.

Then i will see if the DIATOMS apeear again.
Big hug
 
It seems that your pH decreases gradually all through the day. If you have a lot of surface agitation (e.g. from an Eheim Skim 350), then you can add l lot of CO2 but after about 2 hours the pH doesn't increase any more as the injection and surface agitation cause a state of equilibrium. You waste more CO2 but the level is more stable and you also get more O2 to keep the fish happy.

P
 
Paulo, look at this picture:
co2.jpg
The first chart represents the CO2 levels during 2 days if no aeration is being done.
The second chart represents the CO2 levels during 2 days when I do ripple the surface by spray bars.
As you can see, if your aeration (surface rippling) is not sufficient, then your CO2 concentration will increase slowly, and finally reaches some dangerous levels (80 ppm CO2 in my case at the end of the photoperiod). But if I use surface rippling, part of my CO2 degass, BUT as a result I have very stable CO2 levels during whole photoperiod (see the second chart) => in this case the CO2 concentration remains at 35 ppm during whole photoperiod ... no problems with too high CO2 levels, no problems with my fish.

So if you want a constant CO2 level, then you NEED to use some kind of aeration in your tank! According to my tests, the air stones don't have any measurable impact on CO2 levels, so it is best to use spray bars for the aeration or wet/dry filters.
 
pepedopolous said:
It seems that your pH decreases gradually all through the day. If you have a lot of surface agitation , then you can add l lot of CO2 but after about 2 hours the pH doesn't increase any more as the injection and surface agitation cause a state of equilibrium. You waste more CO2 but the level is more stable and you also get more O2 to keep the fish happy.
Click to expand...


ardjuna said:
Paulo, look at this picture:
co2.jpg
The first chart represents the CO2 levels during 2 days if no aeration is being done.
The second chart represents the CO2 levels during 2 days when I do ripple the surface by spray bars.
As you can see, if your aeration (surface rippling) is not sufficient, then your CO2 concentration will increase slowly, and finally reaches some dangerous levels (80 ppm CO2 in my case at the end of the photoperiod). But if I use surface rippling, part of my CO2 degass, BUT as a result I have very stable CO2 levels during whole photoperiod (see the second chart) => in this case the CO2 concentration remains at 35 ppm during whole photoperiod ... no problems with too high CO2 levels, no problems with my fish.

So if you want a constant CO2 level, then you NEED to use some kind of aeration in your tank! According to my tests, the air stones don't have any measurable impact on CO2 levels, so it is best to use spray bars for the aeration or wet/dry filters.
Click to expand...

I agree with this also. My experience has always been that adding CO2 causes my pH to drop indefinitely, it would never stop dropping and was impossible to keep it at a set level.

It took a long time for me to figure out that my surface agitation (although present) was not enough. Now I am using a spray bar just below the water level, my CO2 drops from 8 to 7 and stays there until CO2 turns off, before it would drop as low as 6.2 (200ppm).
 
thanks guys for the reply. I just ordered ADA aquasoil to handle the high KH and GH. I adjusted the light to 7,5 hours a day and let the CO2 the same way.
I removed a lot of dead leafs and cut the monte carlo. they start to pearl at the last 2 hours of the day.

But I'm going to change the substrate because the substrate that i have now contains a lot of silicate.
Im putting 3a4 bps of CO2 and have a nice rimpling of the surface due to the spray bar. So the fish aren't on the surface of the end of the day.

I will keep you posting and in the meanwhile I'm reading a lot of the forum here so thanks everyone
 
Hi guys,
Fisrt of all in my name and Angelo´s thanks for reply.
After all i have writen and said i made that with the co2.. Is on a level that i can´t push more.
Still, cause of the 9 KH and as i also told before the pH didn´t drop a 1 Ppm .

Angelo: It drops from 7.6 to 6.8.
But this doesn´t worry me at all brother, cause with this Kh i (we) wont have to much flutuation in the ph.
The drop is a lime green. Even with this Kh we can reach high levels of co2. The problem is the time to get it there and how...

My conclusion after a good looking to the tank: Diffuser!
To get this Co2 level i really need to open the "mouth" of the valve cause my diffuser is a pretty good blahblahblahblah.. . and i can´t increase more flow to the tank cause i dont´want to see the plants doing the mambo dance inside. And yes the Outflow does move the water doing aeration also.

So Angelo: as regarding the Co2 and flow my opinion is the same i allready give to other friends of us.

If i don´t buy a very good difuser/reactor to really break the co2 i or we wont´t get there.Cause if you have large bubbles coming from your difuser you will have losses of co2 and hard time to dissolve it in the tank.
The more the bubbles are break inside the difuser the best. Like dust coming out is perfect, cause than yes the co2 is imediately dissolved and become as part integrated of the water, as soon as he comes out of the difuser, and few losses (almost zero) to the surface. As few losses to the surface of Co2 than you wont have to worry of geting high levels of flow at the surface creating more o2 to fight the co2 coming to the top.
As of course with Co2 being pretty well integrated as soon he comes out of the difuser, than is in the water itself. And then we wont need an amount of circulation. Just enough to see plants moving a little bit. Just a little bit.

I look at this otherwise:

The more big bubbles of co2 i have coming of the difuser, the more time i need to force them ciuculating in the botom so they can explode under before getting the surface. And as most people have this issue what they do?
More flow! To force them being in the bottom cause they need more time to explode/dissolve.... 😉

This is my opinion. And this is what i will change The Diffuser!. I allready bought 4 diffuser in the past year..(Aquagro + Gush + Aquaeden + Rhinoxx 5000) and none of them makes what i see in a ADA...

There we go to a certain lesson i allready have very well presented in my mind..... in this hobby trying to "Save money" is worst then spent imediately.. lesson learned. ADA on it´s way...

Many thanks to all and i will retrive you news.
 
Hi all

Interesting discussion 🙂

@ardjuna : do you have a link to that research paper regarding pH and algae? Just out of interest.
And how did you determine that your friend has 15ppm of CO2 in his tank?
 
You must log in or register to reply here.
Back
Top