Lighting

[shmeeb]

I recently had a pretty severe diatom problem. I tried various methods to alleviate it but the only thing that really worked was turning off my 10K bulbs (2x65 watt) and using just my actinic (2x65 watt). The diatoms have completely cleared up, and I had a massive influx of coraline algea. I only have one coral in my tank (my first one), and he's making a come back as well. My question is should I turn the 10K bulbs back on, replace them with 50/50s, or replace them with actinics (that might be a bit dim)? What do you guys think?

 

[kevin j]

Yes turn your white lights back on. Your corals need the white light just as much as they need the blue light. Your diatom
is not because of your white bulbs the problem is somewhere else.
Diatoms feed of phosphates I think and I know they do off sicicates. Do you use tap water if you do switch to ro. If you use ro how good are the filters? I hope this helps
kevin

 

[wrassecal]

You mention your "first" corals. How old is your tank? Diatoms are a normal part of tank maturation. I'd advise turning the lights back on, the tank is going to need to stabilize to the full conditions of lighting. And I'll second the ro/di water so that no phosphates/silicates enter the tank and feed the diatoms.

 

[shmeeb]

The tank is just under 2 years old. I converted from an FOWLR setup at the start of the summer. At that time I had about 50 lbs of LR. The first thing I did to convert was get an RO/DI unit and about 40 more lbs of LR. Then in August I upgraded the lighting to a 260 watt PC, shortly thereafter (about 1 week) I started seeing the diatoms. I can't think of anything that changed aside from the lighting. I did some large water changes and the diatoms would stay gone for about 4 days. I started doing 10% water changes weekly, which kept them somewhat under control. I had bought some yellow polyps, which did not do well. About 3/4 of the polyps died. Latley the remaining polyps have made a comeback. You think maybe the weekly water changes had a gradual affect?
Oh, I did have diatoms when my tank was first getting established, lasted about 2 weeks then didn't see them again until this latest bloom.

 

[shmeeb]

Just some info:
Its a 55 gallon tank, running a ps/2 protein skimmer, 3 power (heads about 700 gal/h between them), and a fluval 404. Residents are 20 turbos, 5 scarlett hermits, 2 sally light foots, one bi-color blenny, and a hippo tang (I'm told I'll probably have to remove him eventually, which is too bad, because I put a lot of work into that guy when I first got him--and he's a beaut).

 

[kevin j]

Everything sounds ok but test your water for silicates. One other thing that i can shed light on is your ro unit itself. what kind of membrains do you have for the pre-filter is it a .5 micron or 1 micron because the .5 is 100 times better then the one micron also the ro membrian i know through spectrapure if you buy the better membrain which is only 10 dollors more it says it takes out silicates which the cheeper one I dont think says this. Same thing the the di resin the cheeper one does not pull all the stuff out that the more expensive one does. So you have a ro/di unit but its probably not pulling everything out that it could.
kevin

 

[wrassecal]

Yes, you should make sure your ro unit is properly working. It is possible you are experiencing the diatoms from the changes you have made over the past 3-4 months. When I upgraded tanks and changed lighting, added live rock etc I battled diatoms blooms for about 3 months. It almost drove me nuts and there is a lengthy post on here about it. If it would help search for the thread "whole new meaning to diatoms" there is a lot of good advice on that thread. Here is what it looked like at about the 3 months mark after changes....