Cyano triggered by scrubber? (from thread on RC)

[maglofster]

Found this in a thread on RC. Any truth in this?


[i]I would instead speculate (from Hans Werner above) cyano grows when phosphates are spiked from foods and nitrates are limited.The carbon source will remove both phosphate and nitrates. Here is how I succeeded in removing cyano.

Blue-Green algae are well known to bloom in freshwater tanks when growth of vascular plants is nitrate limited. The issue you are seeing is tank is nitrate limited, not phosphate limited. I suspect the same is true in reef tanks.

I use Tropic Marin Pro with BRS 3 part recipe with an algae turf scrubber that is heavily cropped with high flow through. I went through a period of a cyano bloom for several months, however carbon source was DOC from Turf Scrubber not Actif. They were leached sugars and starches.

1) To reduce it I first created calcium as supersaturated condition. Kalk naturally does this but with 3 part raised caclium greater than 420 and carefully left kH 7-8. This will accelerate coraline algae.

2) Iron Gluconate to feed algae turf scrubber.

3) Microbe Lift Special Blend 20/cc per 180 gallons per day. Use of mineral flocculant is options.

4) Reduce feeding to every other day of only heavily rinsed frozen foods.

5) Wait 3-4 months. Yes thats how long it took. I have almost no algae and will increase feeding again now.

I would not add Iron if you don't have a large ATS that needs it. I discontinued after ATS growth slowed with it. Red turf algae also faded. I only have volonia as nussiance now. I had stubborn cyano that was on rocks not sand bed. It was also red turf mixed in.

[SantaMonica]

carbon source was DOC from Turf Scrubber not Actif. They were leached sugars and starches.

This part is true. Algae puts DOC (proteins, amino acids, vitamins and carbohydrates) into the water. Carbohydrates (mostly glucose) is the same as carbon dosing.


Iron Gluconate to feed algae turf scrubber

This is true. Any iron will help, usually, especially if the growth is yellow. May not be needed if you feed nori.


Microbe Lift Special Blend 20/cc per 180 gallons per day.

Probably not needed, since the DOC already greatly increased bacteria (and thus microbes) to food-limiting levels. Just like in oceans and lakes, the microbial loop (bacteria <--> DOC) controls how many microbes there are.


Reduce feeding to every other day

This is what is actually removing the cyano (because the scrubber is not strong enough by itself).


of only heavily rinsed frozen foods.

Not important. There is far more carbon in the food itself (and the DOC from the algae) than there is in the little bit of rinse-off from the food.


I only have volonia as nussiance now.

An indicator of a scrubber that is not strong enough (for how much he is feeding).

Basically, cyano is the last algae to go, but it will go if your scrubber is strong enough (for how much you are feeding).

Note: Feeding liquid coral foods requires much stronger scrubbing.

[maglofster]

Ok, interesting stuff since I'm fighting cyano in one of my tanks.

[Vannpytt]

I have slight brown slime on parts of my sand, but no algae growing on rocks etc at the moment. I havn't had it for a while since the scrubber started growing green.

I did increase feeding dramatically the last month and this triggerd the small patches of brown film om sand and glass. It is getting better already though, and I don't really worry about it. Sure, it does not look sterile at the moment, but that is not my goal either. My sump is filled with filterfeeders, my SPS are growing very nicly (10-15 colonies of acropora sp, and montipora sp.)

I do tend to keep calcium in the upper range also, but do not change any water.

[iggy]

Funny that this was my original post on RC where I spend little time any more. I am sort of planning long term maintenance free solution to my reef tank. Not sure I implied ATS causes Cyano though.

My assumption currently is cyano growth occurs with either DOC alone or with excess phosphates. I do not agree it is a sign of excess nitrate as many tanks are before applying and ATS.

I like the idea of increasing scrubber size, but at the same time it may not be necessary if the aquarists weekly croppings are reasonable or light and cyano remains. I suspect the aquarists simply needs to supply the growth limiting nutrient to better uptake phosphate.

1) My solution is to temporarily reduce DOC with carbon.
2) Apply iron gluconate for two weeks at 0.05 ppm and notice any effect on scrubber.
3) apply daily dosage of 0.05 ppm Calcium Nitrates if AND only if nitrates are non-detectable with high quality test kit such as LaMotte.

The Eheim liquidoser is ideal and this simple recipe is experimental to increase ATS efficiency, so use at own risk of course. My opinion of ZV Coral Snow and Microbe Lift Special blend is still out. Coral snow will create effect of removing additional DOC from water on the first few trys and does little else otherwise.

I do think it is critical to thaw and rinse frozen foods. I am not concerned about carbon conent of food but removing the 90+% water that is nutrient rich. I will continue to do this.

[SantaMonica]

Feeding less will accomplish the same things. It's easier to feed less than use carbon.

And, I don't think rinsing the food helps. There is far more contained in the food itself, than the little bit of water around the food. Again, just feeding less will do more.

[iggy]

The purpose of ATS is to be able to feed more.

Trading algae for cyano is essentially already been accomplished by carbon dosing.

[SantaMonica]

I think the idea is to get rid of it all, which it will do if the scrubber is stronger than the amount of food being fed. Also, scrubbers work best in low-nutreint environments because of green flow-through growth; so by feeding less for a while, the scrubber gets stronger (greener), phosphate comes out of the rocks faster, and cyano eventually goes away; then you can start feeding more like the original plan. But in the mean time the scrubber has to deal with high-nutrients leftover from the previous setup.

[iggy]

What is the time frame for cleaning up previous set up?

It has been since last September and tank went through a phase of very low algae and cyano. Only cyano returned. I discontinued all liquid foods and cut feeding by 2/3rds. I have to change about 5 gallons every week to remove returning cyano.

I will likely use carbon to remove DOC at least short term. SPS growth is fine overall and tank is not a mess overall.

[SantaMonica]

Sounds like your scrubber got weaker. Happens to a lot of people as their bulbs and pumps weaken.