Because I suffered such a huge outbreak of diatom algae with my last tank, I decided to see if I could replicate it on a smaller scale and see exactly how much damage, if any, it would do.
I picked up a 10g tank and filled disposable plastic containers with the same substrate as my main tank (aquariumplants.com black diamond). I left 1/2 the tank as a bare-bottom.
I planted some stem plants in the substrate and left some floating. I put in a thermometer and set it as the same temp as my main tank. However, I did not add filtration or CO2. Lighting came from 1 60w spiral florescent bulb 7 hours a day.
I did a 100% water change once a week using water from my main tank. My main tank gets full-sope fertilization and it gets it heavy.
After 3-4 weeks, the Brown algae was at its worse.
Oddly, most of it formed over the half of the tank that had the substrate. This makes me wonder if the Black Diamond substrate is high in silicates and is the reason for the large amount.
Now lets skip to 5-6 weeks and we have this
Now it is turning white and dying. I added nothing to the tank but replacement water each week. The lighting has remained the same.
Best thing is that all the plants survived. Some that were red turned green, but thats about it.
I have never seen such large blooms as the ones like this and in my main tank as well as a grow out tank. Not claiming this is a very scientific test or anything, but it does get me thinking.
Does the aquariumplants.com substrate contain massive silicates?
Would it be best to let as much of this algae grow as you can stomach and let it starve itself out faster?
Mr Barr says it has nothing to do with silicates. I hope he chimes in here. I am really interested in why these blooms are so much bigger than any tanks I have ever had (30 years worth).