Cyanobacteria Identification - At Last!

jaypeecee

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Hi again!

Along with the UV-C sterilizer, it will still be necessary to use Easy-Life Blue Exit. May I also request that UKAPS members keep this within UKAPS' four walls? I don't want someone else nabbing the idea and claiming ownership of it. I don't seek to benefit from it other than to, perhaps, help others win the battle against the blue-green menace. But, at the moment, it's a one-off. It has worked for me and that's all.

JPC :)
 
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I just thought I’d share the results of my experimentation with nutrient ratios in relation to cyanobacteria. I believe the ratio of NO₃ and PO₄ may be important.

To start with, I was dosing TNC Complete at the “double-triple” dose as recommended by Aquarium Gardens. Roughly speaking this results in about 40 ppm/week of NO₃ and about 3.7 ppm/week of PO₄. In other words, this is very rich in both NO₃ and PO₄ and not far off a 10:1 ratio. With this dosage I was, not surprisingly, getting good plant growth - and I was getting no Cyanobacteria at all.

About eight weeks ago, I decided to stop using TNC Complete and go with DIY salts instead, because I’d read up about red plants being redder when NO₃ is restricted, and I wanted to make my Rotala wallichii go a bit pinker. So I started using KNO₃, KH₂PO₄ and K₂SO₄ to give me 15 ppm/week of NO₃ and 3 ppm/week of PO₄ - so quite a big reduction in NO₃ and a small reduction in PO₄.

Under this regime I was still getting good plant growth, but I started noticing small pockets of Cyanobacteria, particularly near the tips of stem plants in the brightest parts of the tank.. When I say “small pockets” I mean a few square millimetres that never really got any momentum going. I also got green dust algae growing on the front glass very rapidly indeed, which I hadn’t had before.

You often hear that Cyanobacteria is caused by ”low nitrates”, but I wondered if it’s actually the ratio between nitrate and phosphate that is the controlling factor. So about three weeks ago I decided to alter my dosing. I left the NO₃ the same at 15 ppm/week, but I lowered the PO₄ to 2.0 ppm/week. Plant growth is still okay, but the small pockets of Cyanobacteria have packed their bags completely. Also, the green dust is now much slower.

So it appears that the reduction of PO₄ has booted out the Cyanobacteria. But it can’t be the level of PO₄ that was the problem, because originally under the “double-triple” dose of TNC Complete I had a much higher level of PO₄ but no Cyanobacteria. So I think it must be the ratio of NO₃ and PO₄ that created conditions that made it just about possible for Cyanobacteria to get a tiny foothold.

If I’m right, then a NO₃-PO₄ ratio of 10:1 gave no Cyanobacteria, but when that ratio was 5:1 it could just start to survive. I’m now at a ratio of 7.5:1 and I’m still cyano-free.

It also looks like green dust algae might also be exacerbated by a low NO₃-PO₄ ratio.

Note that I’m not suggesting that plants care about the ratio. I think from their point of view all they want is “enough” NO₃ and PO₄ - but some types of ”algae” including Cyanobacteria do seem to care.

I’m going to be sticking with 15 ppm/week of NO₃ and 2.0 ppm/week of PO₄ for the time being. My Rotala wallichii has gone a nice pink colour and everything is growing nicely. I don’t feel like taking the risk of lowering NO₃ further, although it might be an interesting experiment to see if the Cyanobacteria were to come back. If I do decide to try it, I’ll report back.
 

jaypeecee

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Hi @Dr Mike Oxgreen / David

That's fascinating and I'm really pleased that you have shared this with everyone - myself included. You may have made a significant discovery. That's my initial response. Now, I'll go back through your post to assimilate the detail.

JPC
 
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jaypeecee

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Hi @Dr Mike Oxgreen

1 As well as dosing measured amounts of nitrate and phosphate, did you test for each of these nutrients in the water column? I seem to recall that you use JBL Test Kits - if so, are these what you used in this instance?

2 For completeness, what form of nitrate (e.g. KNO₃) and phosphate did you use?

JPC
 
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1 As well as dosing measured amounts of nitrate and phosphate, did you test for each of these nutrients in the water column? I seem to recall that you use JBL Test Kits - if so, are these what you used in this instance?
I use API 5-in-1 strips for most purposes (although I use the JBL titration tests for KH and GH when I want more accurate results). The API strips only give a crude measurement of NO₃ and don’t give PO₄. So my “results” are based purely on the ppm/week that I’m adding to the tank. However, I know from TDS measurements that the water column is in a stable equilibrium: around 200ppm just before water change, and about 160ppm just after, and these numbers stay the same from week to week.

2 For completeness, what form of nitrate (e.g. KNO₃) and phosphate did you use?
That’s right - I use KNO₃ for nitrate, KH₂PO₄ for phosphate, and I top up the potassium to 30 ppm/week using K₂SO₄.
 
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Perhaps you could try the experiment in jars with some stem plant trimmings, rather than risk upsetting your tank.
I could do, but actually I think curiosity will get the better of me and my next move will be to lower the nitrate to 10 ppm/week while leaving the phosphate at 2 ppm/week. This would give a NO₃/PO₄ ratio of 5:1, which is the same ratio that gave me small pockets of Cyanobacteria (at 15 ppm/week and 3 ppm/week). I’d very much like to see whether the Cyanobacteria will return, and it was only a tiny amount so probably worth the gamble! :)
 

rebel

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I've used a similar product to Blue exit without UV-c and had complete clearance of cyano. UVc is optional while the other product is not. It is my only recommendation these days for people who are otherwise busy.
 

jaypeecee

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Hi @rebel
I've used a similar product to Blue exit...
I'm not aware of any other anti-cyanobacteria/anti-BGA products based on salicylic acid, which is what Blue Exit uses. Which similar product did you use? Are you referring to Ultralife Blue-Green Slime Stain Remover, for example?

JPC
 

Ray

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Hi @Ray

ADA do not appear to disclose the active ingredient(s) in Phyton-Git-Plus. But, a 500ml bottle of this treatment will set you back a very substantial 199 Euros! A 500ml bottle of Blue Exit is currently priced at £11.54 from Amazon UK.

JPC
They do not disclose.
The dose is 1 drop daily per 20 l of aquarium water to prevent diseases. In case of blue-green algae infestation, apply 1ml directly to the affected areas - so a 50ml bottle will go a long way!
Some people https://www.ukaps.org/forum/threads/a-new-start-continued-progress.59973/post-593060 think it contains vinegar.
 
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jaypeecee

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Hi @Ray
In case of blue-green algae infestation, apply 1ml directly to the affected areas - so a 50ml bottle will go a long way!
Ah, it's a direct application treatment. As cyano/BGA often occurs on the substrate in sheets, then the ADA product is not a practical option. It might be better suited to BBA for which, I think, some people dab on liquid carbon products.

JPC
 
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