Purple algae

[mrsjoepie]

Could someone please help me out here? For about a month now there has been then purple colored algae growing all over my LR/LS. It's like a film and it spreads quite rapidly also. I don't like it and would like to get rid of it, if anyone can help me out it would be most appreciated.

[DeeZeal]

Sounds like cyanobacteria. There are many things that can cause it to get out of hand such as excess nutrients in the tank, stagnant water, etc... Can you describe your tank?

[mrsjoepie]

Hi DeeZeal,
I have a 75 gallon, LR/LS. The tank is actually at my workplace. I have 2 clownfish, 2 powder blue tangs, some chromies and a lawnmower blennie. I have a few snails and I sand starfish. It has the bio balls and sump along with a protien skimmer. Unfortunaltly the water is cold all the time because I work in a dental office and the air conditioner is constantly running high. I have stressed to all here but no one cares. I do 10 gallon water changes 1 per week. If you need more info please let me know and again ty for your help.

[revrenhex]

How cold is cold? How much do you feed, how often? What kind of lighting do you have? How much water flow do you have going from the sump back to the tank (gph)? Do you use an additives? Have you done anything thus far to combat the purple stuff? What kind of skimmer (brand, size)?

-Cliff

[DeeZeal]

Yeah, what he said. :)

[bertoni]

Does the purple stuff rub off easily? If not, it could be coralline, although it does sound like cyanobacteria.

[mrsjoepie]

it comes off very very easily. I should look up that cyanobacteria shouldn't I?

[Spuds725]

Coraline spreads painfully slow-- Cyano is my guess.

#1 increase circulation-- treats symptoms and not the cause-- cyano will just find the low flow spots.

#2 Reduce nutrient level- will need to get a better protein skimmer (I'll bet), get rid of the bio-balls (slowly or you will cause a cycle) and make sure you have plenty of live rock-- I'd get rid of one of the tangs-- thats too small a tank for 2 IMO and they are poop machines-- ease up on the feeding if you are feeding too much-- if feeding frozen food, thaw in fresh water, pour through a fine net and then put the food in the tank with the net--

If you are using Tap water--stop-- get an RO/DI unit...

If the water is cold-- you obviously need a better (or more) heaters-- raise the temp slowly when you do-- if you are at least 76 then you should be fine (just avoid temp swings)

[bertoni]

Originally posted by Spuds725
Coraline spreads painfully slow

Oh, I wish that were true...

How much food are you adding per day?

Another approach is to add a macroalgae area. Growing and harvesting macroalgae can work very well, IME.