Diatoms??

[spamvicious]

My tank is 9 weeks old. A couple of weeks ago I had some brown algae which I think were diatoms on the rocks. I introduced a small cuc and it cleared up. It’s now back again and is covering all the rock and some of the sand. Today I did a 10% water change and cleaned the surface of the sand where the brown algae was. It looked better and I went out. I’ve just got back and within four hours the sand has more algae on it than before.

I know this is probably the ugly phase but I don’t want it to get out of control and take over the tank. Or do I just have to leave it?. I’m running TMC Pulsar sps8 lights on 50% as they are very bright, do I need to turn the lights up or down?.

 

[Bucs20fan]

I would dim the lights a tad, as they are not needed at this state. Diatoms can grow very fast, one of the reasons we use diatoms to out compete dinos. Are you using RO/DI water?

 

[spamvicious]

I would dim the lights a tad, as they are not needed at this state. Diatoms can grow very fast, one of the reasons we use diatoms to out compete dinos. Are you using RO/DI water?

Yeah I get it from my LFS.

 

[Bucs20fan]

Yep, lower your light output a little, probably 15 or 25% but be aware, diatoms will always come back until they use up all the silicates in your system. So its either deal with them now or later.

 

[spamvicious]

Yep, lower your light output a little, probably 15 or 25% but be aware, diatoms will always come back until they use up all the silicates in your system. So its either deal with them now or later.

Should I do a test to see how much silicates?

 

[Bucs20fan]

No not at all, not necessary by any means, we all had silicates in our tanks when starting, comes from your rock and sand. Perfectly natural thing going on right now. Silicates are not harmful to fish or corals unless a huge concentration of them.

 

[spamvicious]

No not at all, not necessary by any means, we all had silicates in our tanks when starting, comes from your rock and sand. Perfectly natural thing going on right now. Silicates are not harmful to fish or corals unless a huge concentration of them.

Ok thanks. So basically just a wait and hope it clears up?

 

[Bucs20fan]

You dont have to hope, with it being diatoms it will clear in time.

 

[Bucs20fan]

Just another good part of the uglies LOL.

 

[spamvicious]

Just another good part of the uglies LOL.

After having tropical tanks for so many years it seems to odd to have all this algae and not to do anything about it haha

 

[Bucs20fan]

I feel you, I was an avid tropical fish keeper and this was a totally new ordeal

 

[vetteguy53081]

After having tropical tanks for so many years it seems to odd to have all this algae and not to do anything about it haha

Agree with comments posted. Reduction of light help. Diatoms are a brown algae that typically appear in a reef tank that has just completed its cycle but they can also appear in an established reef tank. They can cover sand, rock, pumps, glass, you name it. Diatoms look ugly but in most cases they are harmless so the key is to not panic when they appear.
Diatoms feed mainly off of silicates but also consume dissolved organic compounds, phosphate and nitrates. Unfiltered tap water can contain silicates and is a good way to jump start a bloom if you use it to mix salt or to replace water that evaporated from the tank. The best way to prevent this from happening is to filter water through a RODI unit, although you can still get a diatom bloom when using RODI if the cartridge that removes silicates expires.
Diatoms are typically harmless to a captive reef and can be beaten once their food source expires. Once you put the kibosh on the source, the outbreak should last a couple of weeks so just be patient and it will pass.

Some cleaner crew to help control it are : Cerith snails, Nerite snails and Trochus snails and also Astraea snails are effective at removing diatoms.