battling Rust on tank..any suggestions

[jayzz]

Hi

I have a 20 gallon tank with Rust kind of alge that keeps growing on Rocks and tank. I would wipe it out and it comes right back.

I been using RO/DI water since day 1 and my nitrates are always detected below 10.

my Alk is around 8
Cal is 480

I dont' have much corals except a few frags of frogspawn and hammer and gsp, they seem to be growing very well. Anyone have any suggestions?

thanks

[Otter]

Have you got any macro algae in there? I had a problem with it for a few months, myself, but macro algae and slightly reduced lighting periods seem to have worked for me.

[fkshiu]

Do you have a picture of it?

Is it kind of fuzzy and seems come and go as the lights are on and off? If so, then it's probably cyano bacteria. Manually siphon out and increase your flow to get rid of. Also reduce feedings and/or bioload and start a refugium with macro-algae. If that doesn't work then consider more aggressive nitrate and phosphate control techniques such as granular ferric oxide or bacteria pellets.

[jayzz]

hey

I been doing the lights 6 hours a day and basically feeding just a few small pellets to my wrasse and goby, clown a day for a month or so. but not really working. Weekly 5 gallon water change.

I'll see if I can take a picture when light is on. I dont' think is fuzzy, I can basically wipe it off with my hands more like brown slime. It does seem to disappear on the rock when lights are off. As soon as lights come on for 2 hours or so it appears.

I have a Aquaclear 110, I have tried putting Cheato in it, but dont' seem to stay alive or somehow end up in my tank. I have just some chemipure inside it now and 3 pieces of rock and a aqualite skimmer.

I'll try adding some more flow in the tank.

thanks

[jayzz]

is this cyanobacteria? some kind of rust alge

[fkshiu]

Probably diatoms.

Think Geek: The Nano Reef Project: Diatoms: What's all that brown crap?

About Brown or Golden Diatom Algae - What Makes Brown Algae Grow and Solutions for Eliminating This Problem in Saltwater Aquariums

[jayzz]

thanks, do you think I need to increase flow in my tank. I am currently using a kor 2 and a Aquaclear 110.

The aquaclear 110 I have chemipure and phosguard(seahem). Anything else I perfer not to put sand or macro in there.

[fkshiu]

You should have enough flow for a tank of your size with the two K2s, but it wouldn't hurt to add a bit more. The Aquaclear doesn't count because it doesn't provide any actual "flow" around the aquarium. It just spills water in a single spot. I would actually remove the Aquaclear and all of its media. The Phosguard especially is concerning because it is aluminum-based and has been shown to be detrimental to corals in some circumstances. Seachem doesn't even market Phosguard as appropriate for reef tanks the last time I checked. Granular ferric oxide (GFO) is the standard phosphate removal media for reef tanks. You can run it in the Aquaclear in a bag, but it is optimized to run in a media reactor.

You didn't mention if you had a skimmer. Skimming out dissolved organic compounds (DOCs) should be high on your priority list.

Secondly, your calcium is quite high at 480. What test kit are you using? At levels that high you could see precipitation in the water column. Is your sand clumping? Also, what is your magnesium level?

You can also take a turkey baster and blow the diatoms off of the live rock and then siphon out during water changes. This may prevent the diatoms from re-gaining a foothold.

Add a bit of macro algae is another thing you could try.

Be patient and try a number of strategies.

[neven]

couldn't he just load up the AC filter with live rock? mightaswell use it if he has it

[fkshiu]

couldn't he just load up the AC filter with live rock? mightaswell use it if he has it

He could. It's probably more effective if he turned it into a mini-refugium like I used to have by adding LR rubble, some macro and put a small light over it.