# Algae in non-planted tank



## Tom (25 Apr 2010)

Yet again, it's ages since I've been on here! Thought I'd post on here about some algae problems I've been having for ages in my non-planted puffer tank. 

*Background Info*

It's a yucky Clearseal 120cm, 125 liter tank and houses a solitary Hairy Puffer (Monotrete baileyi). The decor is just rocks with the odd piece of wood. Substrate is Kiln Dried Sand from B&Q which I nearly always use for tanks. Filtration is a Tetratec EX1200, which is waaay over-rated for this size tank, along with a Stingray internal at the other end to knock out the dead spots. 

The Puffer get's fed a couple of mussels per week, and that's it, although he is a bit messy with them - didn't seem to matter much when the tank was planted. Water changed weekly or fortnightly, 50%. It's mature now, over a year old. I've had the fish nearly 4 years. 

*The Problem*

Loads of Blue Green Algae and Hair Algae (Cladophora?). As you can tell from the filtration, there is a fair amount of flow in the tank, which seems to rule out lack of flow causing the BGA. I also use the same sand in my low tech planted tank which is much newer, which should rule out the sand leeching silicates which I've also heard can be a cause of BGA. I'm recording no ammonia, and low nitrate which is good. But why so much algae? It grows as fast as I pull it out. 

*Pictures*

Bear in mind this is after cleaning the glass - the water isn't usually this skanky!










Anyone got any more thoughts on why I can't shift this algae?

Cheers,
Tom


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## George Farmer (25 Apr 2010)

Hi Tom

I'd say although you're not reading ammonia with your testing, it doesn't mean there isn't some there to feed the algae, especially as your feeding regime is 'ideal' for small ammonia spikes.  So the ammonia is safe levels for the fish, but the algae is able to utilise it.

I'd consider a 5 day total blackout, before which you can remove and thoroughly clean your decor with bleach etc.  Thorougly rinse with fresh water and soak in de-chlorinator/water too.

Clean your filter before and after the blackout too, as well as change 50% water before and after.

Then to help minimise further algae problems consider only using tank lighting when viewing the tank, and using phosphate removal resins.

Or consider have a lot of floating plants to shade the aquarium and help with nutrient removal.


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## dw1305 (27 Apr 2010)

Hi all,
I'd agree with George, 





> I'd say although you're not reading ammonia with your testing, it doesn't mean there isn't some there to feed the algae, especially as your feeding regime is 'ideal' for small ammonia spikes. So the ammonia is safe levels for the fish, but the algae is able to utilise it.


 and 





> Or consider have a lot of floating plants to shade the aquarium and help with nutrient removal.


 I also think that if you have sufficient light in these circumstances algae is inevitable, even if you could reduce the nutrient levels to very, very low levels. I get filamentous green algae grow even in the buckets of rain water that have been left outside in the light.

cheers Darrel


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## George Farmer (27 Apr 2010)

dw1305 said:
			
		

> Hi all,
> I'd agree with George...


Phew, that's a relief!!


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## Dave Spencer (27 Apr 2010)

Would phosphate removing resins work in this instance?

Dave.


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## dw1305 (27 Apr 2010)

Hi all,
I've never used them, but the assembled wisdom of this forum would suggest that they won't have effect. Lack of light definitely will work though.
cheers Darrel


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## ceg4048 (28 Apr 2010)

I'd have to agree. The same thing that causes algae in planted tanks must be responsible for blooms in non-planted tanks. My immediate suspicion would therefore too much light. Phosphate cannot trigger algae, it can only exacerbate the bloom once triggered. What is the maintenance regimen and what is the lighting in this tank?

Cheers,


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## George Farmer (28 Apr 2010)

So limiting NO3 and PO4 in a _non-planted _tank has no bearing on limiting the triggering of algae?

What nutrients do trigger algae in a non-planted tank?  Just NH3/4?


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## ceg4048 (28 Apr 2010)

Well, I'm pretty sure that the combination of light + ammonia production rate is the trigger regardless of the tank type. Possibly, the dissolved gas levels are a factor as well. I don't think the algal spores are necessarily aware of what other inhabitants are present. They just sample the chemistry and spectral characteristics of the environment and "decide" to bloom based on their programming. In an environment that is high is NO3, low in stable NH4 production, high CO2, high in O2 and low in light, this could be construed as plant friendly conditions, even if no plants are present. From the perspective of the spores, there's no advantage for them to bloom. On the other hand, if dissolved O2 levels dropped and NH4 production rate was on the rise or fluctuated, or if the lighting rose sharply, this might indicate to the sampling spores that something has deteriorated in the environment and that there is an opportunity to advance.

People don't realize what a powerful impact plants have on the environment. Plants aren't just innocent bystanders. They actively change their environment to suit their needs. They acidify, de-calcify and oxygenate. As long as the plants are healthy they modify the environment in a certain way. Spores read the conditions and wait for the "right" conditions that indicate the health of the system. If the plants are either unhealthy or missing then the water chemistry is not as tightly controlled or as specific.

Now, just to be clear, I'm not talking about specific targeted chemicals that pits one plant against another or anything like that. I'm talking more in the general sense. For example, If I couldn't physically see a tank to determine if it were planted, but if I had remote sensors, one useful sensor would be an O2 sensor. If O2 levels were significantly higher than the standard equilibrium value then that would indicate the possible presence of photosynthesising organisms. I could guess that plants were present. 

NO3/PO4 cannot, in and of themselves _cause_ algae to bloom. They can only be cofactors in a chain of events associated with a bloom, but they are not, by themselves the fundamental causal agent.

In Toms case, if his lighting is high and if there is a high organic waste content, this could easily produce the chemical conditions that trigger a bloom. This can happen even if he were using pure RO water. Granted, removing nutrients helps to reduce the acceleration of the bloom, but by then it's already too late, the trigger has already occurred. Algae are the prototypical gate crashers.

Cheers,


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## plantbrain (28 Apr 2010)

This is easy  

No light= no algae.

Simply turn the light on when you want to see the fish.

No more.

Algae are light limited, saves $$$ in electric.
Much easier, cheaper than any other alternative.

Makes the tank look more natural and nice though IMO.
Floating water sprite would be ideal also, blocks light, mops up nutrients really well, can be sold, traded for fish food, reduces the need for water changes, removes both NH4/NO3/PO4, block light for algae.

So that's the second easiest thing to do.

Adding a wood gnawing pleco, eg Panaque might do well with the puffer.
Or smaller species such as rubber nose etc.

Very good trade off for both of those methods, but the fish solution might not be, depends on the puffer's mood.

Regards, 
Tom Barr


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## George Farmer (28 Apr 2010)

+1 from me, Tom! 



			
				George Farmer said:
			
		

> ... consider only using tank lighting when viewing the tank...
> Or consider have a lot of floating plants to shade the aquarium and help with nutrient removal.


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