Cyano or diatoms

[pat8you]

How do you tell the difference between the two. I have redish-brown something growing on my sand. I tested the water and all the parameters are good, nitrates under 20. I do weekly PWC of about 10-15%. Should i just let it run its course and hope the clean up crew takes care of it? I have 4 nassarius snails for a 14gal tank. As well as 3-4 blue leg hermits 4 turbos and 2 atrial snails. Have light set for 8 hours a day. I have two corals in there right now and i could probably cut down the light a bit or go dark for a day or two if i had to. Let me know what you think.

 

[Kurt_Nelson]

Diatoms are a brownish, rust-like powder. When you disturb them, they blow around like dust.

Cyano can be red, brown, green, blue, and combinations of all those colors and is slimy and sheetlike. Cyano normally has bubbles trapped within it, diatoms don't. The main difference is that cyano is in no way "dust-like."

Snails will take care of diatoms and they'll eventually go away. If it's cyano, it's going to be up to you to find/reduce the cause.

For a reef tank, I wouldn't consider nitrates at 20 ppm "good". FOWLR... maybe. But not a reef. Do you have any fish in that 14g or just corals? If no fish, then what are you feeding/dosing to get you up to 20ppm nitrates?

 

[pat8you]

I have two clowns in there and two small corals (recordia mushrooms, pink pulsing xenia) I think its actually under 20ppm but i just have the test strips that show up different colors so its hard to tell exactly what the nitrates are at. I feed the clowns usually twice a day brine shrimp and pellets.

I think its diatoms then because it doesn't seem slimy. I'll give the snails a couple of days and see if they take care of it. Thanks for the help

 

[Kurt_Nelson]

If you've got 2 clowns in a 12g, I'd invest in some test kits that don't involve the strips. You've got a lot of load in that tank and I think you want to have a really good idea what your water parameters are. With such small water volume, you really don't have a lot of "wiggle room" with letting your water quality slide.

I suppose mushrooms and xenia are pretty forgiving when it comes to water quality, but you should still strive to keep those levels pretty low. You can cut back to feeding once a day... others here will probably even tell you once every other day. Might want to consider switching the brine shrimp to mysis shrimp also... more nutritional bang for your buck. Somewhere I read that fish living on brine shrimp is like humans living on popcorn. Not sure if they meant plain, or with lots of butter on it. (Yum!)

 

[pat8you]

Thanks. Yeah i keep a pretty close eye on the levels. I was feeding more often before since i just set up the tank a month or so ago and wasn't sure how often i should feed. I think that is contributing to the nitrates being high. The other levels stay at zero and i've been watching them closely to try and get a feel for the bioload on the tank. I'm pretty new to keeping corals. At about what level of nitrates will it start causing the corals stress. I'm only going to be keeping relatively easy to care for corals (soft, polyps, mushrooms, LSP) nothing touchy like SPS which i don't have the light for anyway. I will have to pick up some mysis next time i need food. I also feed pellets and sometimes some flake food to mix up their diet. Thanks for all your help kurt

 

[melosu58]

Cyanobacteria, AKA Red Slime Algae

 

[johnmaloney]

How old is your tank? If it is young then diatoms are your problem, if it is older probably cyano. Kurt's post should get you a positive ID. Nassarius snails only eat fish waste and leftover food. They don't eat algae, diatoms, or cyano. Blue legs don't get rid of diatoms either. You need a stronger CUC. Try to find a few ceriths at the LFS. Great for diatoms and cyano. Very versatile snail. Get at least 10-12.