DIY diatom filter


Guru Class Expert
Sep 6, 2008
between Sac and Reno
I have a magnum hot shot filter. I was thinking of adding DE to the micron filter. I'm just not sure how to do this. Would I run the filter say in the sink with a bowl of DE to prime it? How do I know when there is enough DE coating? Could I then take it to the tank and run it for a few hours? I am guessing that adding DE would improve the micron filter but am not sure it's worth it. I know I will have to remove the filter from the tank before I turn it off. I don't want back flush of DE.

On the other hand would it be worth to just buy a silicate/ Phosphate remover an it to the canister?

The reason I am doing this is I have a ton of brown algae. My oto can't keep up. I must have done a mini cycle. It is acting just like a new tank. My phosphates are off the scale but not from the tap. I have given it a week with the over dose of excel. It is a bit better.

I know I could wait the time for my tank and new plants to adjust but It's two weeks since this started. I am impatient.


Plant Guru Team
Lifetime Member
Sep 23, 2007
South Florida

You may want to grab the instructions (on the Web if possible) for the Vortex Diatom filter which uses DE and must be primed....

I would not bother with it (except to experiment) and try the following.

1. Do 2 or 3 50-75% WC for 2 or 3 weeks if possible.
2. Increase your c02 and ferts a bit to ensure optimal levels.
3. Cover the sides of the tank if any get any indirect light from a window or door. One of my sides was next to a window and sunlight got in there at various times of the day. Not much, but I think it was a factor......

I had these brown diatoms in my 180 for weeks. Patience and the above regimen eliminated it, and I have not seen it since. I would say not in the last 5-6 weeks, and it was a major PITA before lol

I am now back to weekly WC with EI and c02 and have not seen it since.


Guru Class Expert
Jun 8, 2007
You have only one oto in a 45g tank? I usually stick with one or two per 10 gallons.