Combating diatoms with yeast?

Nigel35 · Jul 21, 2020

I have had outbreaks of diatoms for a while now. I have tried to syphon/vacuum them out but they mostly seem to come back after a day or two. Is yeast a good method of getting rid of diatoms? If so which brand? Will it effect any of my corals at all LPS, SPS etc.? Thanks!

Crustaceon · Jul 21, 2020

The root cause of the problem is low nutrients so first and foremost your goal should be increasing nitrates to 2ppm + and phosphates to .03ppm +. Secondly, the idea behind adding yeast to a tank is that it introduces biological competition that starves out the dinos. The same can be accomplished with a bottle of beneficial bacteria and some vinegar. A problem with doing this with zero nutrients though is that bacteria needs a little n&p to reproduce. So after adding yeast (brand doesn’t matter), it may take a few days for some of that yeast to break down into enough nitrates and phosphates for a portion of that yeast to propagate. This temporarily starves & kills some of the dinos and allows the yeast to use it as food. As stated in another thread, it might take a week before you notice a difference, but keep in mind, without increasing nutrient levels, this is a temporary fix and dinos will likely return after treatment.

Flippers4pups · Jul 21, 2020

Crustaceon said:
The root cause of the problem is low nutrients so first and foremost your goal should be increasing nitrates to 2ppm + and phosphates to .03ppm +. Secondly, the idea behind adding yeast to a tank is that it introduces biological competition that starves out the dinos. The same can be accomplished with a bottle of beneficial bacteria and some vinegar. A problem with doing this with zero nutrients though is that bacteria needs a little n&p to reproduce. So after adding yeast (brand doesn’t matter), it may take a few days for some of that yeast to break down into enough nitrates and phosphates for a portion of that yeast to propagate. This temporarily starves & kills some of the dinos and allows the yeast to use it as food. As stated in another thread, it might take a week before you notice a difference, but keep in mind, without increasing nutrient levels, this is a temporary fix and dinos will likely return after treatment.

Op said diatoms, not dinoflagellates.

Nigel35 said:
I have had outbreaks of diatoms for a while now. I have tried to syphon/vacuum them out but they mostly seem to come back after a day or two. Is yeast a good method of getting rid of diatoms? If so which brand? Will it effect any of my corals at all LPS, SPS etc.? Thanks!

Have you seen this?

Nigel35 · Jul 21, 2020

If Nitrates are at about 5-10ppm and phosphates are at 0.25 (API test kit it could be lower), could it be another issue rather than nutrients?

Crustaceon · Jul 21, 2020

Flippers4pups said:
Op said diatoms, not dinoflagellates.

Have you seen this?

I meant to say diatoms, but the treatment is still the same for dinos/diatoms. Both are low nutrient related issues.

Daniel@R2R · Jul 21, 2020

interesting solution

Crustaceon · Jul 21, 2020

Nigel35 said:
If Nitrates are at about 5-10ppm and phosphates are at 0.25 (API test kit it could be lower), could it be another issue rather than nutrients?

At those nutrient levels, i’d suspect it to be a bacterial issue (most of these are low-nutrient related so your case is an oddball). With a healthy bacteria population an enough nutrients, the beneficial bacteria population should out-compete most everything aside from cyano which can pop up at extremely low & extremely high nutrient levels. I’ve dealt with a similar scenario as yours by dosing beneficial bacteria and a few ml of vinegar. What I wanted to see a few hours later was a slight haziness in the water. After a week of this I had clean sand again, I stopped dosing bacteria/vinegar and haven’t had a problem since.