Bacteria Bloom after Diatom bloom?

[Doug_E]

My tank water has turned cloudy. It will vary day to day and even hour by hour some days. I recently had a big diatom bloom as well, but that seems to have stopped. Could it be the diatoms are dying and the bacteria are now blooming?

The diatom bloom followed a re-scaping of the tank. I removed sand (which I had washed very well), moved rocks, planted more plants, and otherwise really stirred up the tank. I suspect that lead to silicates in the water which caused the diatom bloom. 

My water parameters have been steady. 0 ammonia for the most part (today it is maybe a smidge above 0 and the water is the cloudiest it has been). 0 Nitrites. Nitrates are now between 5-10 but were up around or over 20 when the diatom bloom began. 

It is a 20 long with 8 small white cloud minnows, 6 blacknose dace (native minnow) that are 1-1.5" long, and 3 amano shrimp. I have several plants (anubias, jungle val, water sprite, java fern, and some others so it is moderately planted). 

The fish seem normal and active. They don't seem to care. 

I also recently added a Fluval 207 in preparation for switching to that filter. Old filter, which is still running at low, is a Tidal 55. Filtration seems to be more than adequate. 

I plan to reduce feeding (was feeding once a day and don't think I was over feeding). I may also add charcoal to the filter. Right now they are both just the sponges and biorings. No chemical filtration (charcoal, Phosphate, etc). 
 

[MickS77]

If your water parameters are fine I'd just ride it out. I don't know if diatom algae would bloom in the water, I always thought it was a surface algae. 

[Doug_E]

28 minutes ago, MickS77 said:

If your water parameters are fine I'd just ride it out. I don't know if diatom algae would bloom in the water, I always thought it was a surface algae. 

It isn't the diatoms in the water, I'm pretty sure of that. With the Diatom bloom seemingly over I wonder if that organic matter is now creating a bacterial bloom. 

I got 3 Nerite snails yesterday to help with the diatoms, and wow...they do a great job in no time. There are already patches of glass cleaned off. Slow and steady, they get it done. 

[Doug_E]

In case anyone else has the same issue, it seems that the diatom bloom is over. It seems to have stopped a week ago (new growth) and just as the bacterial bloom started. I'd say the diatoms did die off and create the food for the bacteria which then bloomed. Today water was much cleared and the evidence of diatoms is much less than it used to be. 

The nerites work wonders too. Now if only I could train them to keep my annubias leaves clean!

[Wes L.]

I had a very similar thing happen to me. It's probably not the silicates, since they're in every drop of water on earth, but you probably let a lot of bacteria out of the substrate when you stirred it up, and that would have been some good nutrition for a diatom bloom. I tried using the Dr. Tim's Re-Fresh/Waste Away combination when I had the issue and it was awesome! It's not a medication or a chemical, but you fight the bad bacteria with good bacteria. It cut my diatom bloom to about 80% to 90% from what it was. I do the Re-Fresh/Waste Away combination about every 4 or 5 months just to make sure everything stays in check and so far it's never failed me.

[Doug_E]

1 minute ago, Wes L. said:

I had a very similar thing happen to me. It's probably not the silicates, since they're in every drop of water on earth, but you probably let a lot of bacteria out of the substrate when you stirred it up, and that would have been some good nutrition for a diatom bloom. I tried using the Dr. Tim's Re-Fresh/Waste Away combination when I had the issue and it was awesome! It's not a medication or a chemical, but you fight the bad bacteria with good bacteria. It cut my diatom bloom to about 80% to 90% from what it was. I do the Re-Fresh/Waste Away combination about every 4 or 5 months just to make sure everything stays in check and so far it's never failed me.

That make sense. I will give that stuff a try next time I have any issues. I'm setting up a 40g and hope to avoid the mistakes I made this time on the 20.