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Phosphate Questions

4167 Views 3 Replies 3 Participants Last post by  kestrel
I've been battling an outbreak of cyano and hair algae for a long time now, with little success. I've cut back on feeding to 2 small servings per week, reduced lighting to ~9 hrs/day, and increased my water change frequency. I've added more snails, only to see them gorge themselves, and grow, but not impact the overall algae population. I also have harvested numerous cups of algae directly from the tank, only to have it return. All of this has seen my nitrates drop, but I still have the problem algae, with no significant reductions.

Although I can't detect phosphates (ever) when I test, could this still be a large part of my problem? I recently read a response from Tom and Chris that indicated that cyano can use enzymes to cleave phosphates from non-detectable forms. Could this be supporting the algae in my tank?

If so, where is it coming from? Is there enough of these phosphate compounds in the food (I use frozen foods) to still support it, even with greatly reduced feedings? Could it be in the Ball's Pickling Lime that I use to make-up my Kalkwasser? I have not tested it, but will try to tonight.

Also, what is the best method for getting rid of phosphates? Since I've tried lots of other options, would activated carbon or phosphate removers work? What brands have people had success with?

Thanks for considering all of these questions-
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from what i understand the kalk actually helps remove phosphate from the water column. i do not know how exactly, but i am sure one of the chem gods can explain.

now galleon has posted an interesting tidbit on the DSB thread about DSB producing phosphates. try going in there and reading about it. now be prepared to have your brain hurt afterwards.:(

Kalkwasser actually precipates the Phosphates. However, how new is your tank. Sometimes the hair algae stage is just part of new tank syndrome and there are no easy answers. If this is a reef, I would like to know what water you are using. I use RO/DI water (5 stage) to make sure I am not putting in anything I don't want in my tank. Also, Watch your bioload, more critters, more nitrates. Crabs and snails I don't count but my wife had the same problem until she lost some fish. The hair algae went away. Also she bought a red-lipped blenny. They gorged on the algae, especially since you feed so low now.
Phos-Gard by Hagen is a phosphate sponge that we use in our sump to rid ourselves of a lot of phosphates. I have never really had much of a problem but I also like using refugiums.


This tank has been moved twice, but has been up for over 5 years now, with the most recent move being 18 months ago. And I only use 4-stage RO/DI well water.

Geoff - Ouch. A person could hurt themselves trying to read that thread. It'll take me a month of study to digest that stuff :D

One thing that I have noticed about the hair algae - It grows predominantly on two pieces of rock that were originally dead coral skeletons. They've been in the tank with live rock for the whole 5 years, so I would consider them to be LR, but they still don't have much coraline growth on them. My Figi LR, does not seem to support the hair or cyano growth at all like these other pieces. Could it be worth changing out the coral heads?

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