Phosophate Precipitation Causing Algae on Sand?

[ufans]

I recently had an algae bloom (green hair) on my sand and was wondering if it could be caused by phosophate precipitation. My level of PO4 is ~.15ppm and I have read that when the PH nears 8.4 that the phosophate in the water can precipitation and bind onto the sand/rock/coral. I don't have algae growth anywhere but on the sand. Could this phosphate that is bound to the substrate be causing the algae growth or is the algae simply caused by the PO4 that is in the water?

Also, what is the solution?

I am going to continue to do water changes, but I have also read that many salt mixes contain phosophate and the addition of only a small amount of food can significantly increase PO4 levels. I realize the ideal solution is to setup a refugium, but that is not an option at the moment. So, what about the chemical removal methods? Is it better to use Al-oxide or Iron-oxide products?

Lastly.. I have been removing the algae growth from the sand by simply netting it out, which seems to help quite a bit. And recently, I have seen some diatom bloom that might be helping??? Does diatom consume PO4?

I have learned more chemistry in this hobby than I ever had in all of my schooling!!!

 

[Kevin1000]

Some people purposely raise their PH (temporarily) to bind the phosphates to rock effectively taking it out of the food chain.

When you have an algae break out you need to keep an eye on excess nutrients which include both nitrate & phosphate.

Not sure what kind of water your using. If RO make sure your filters are working. If tap water - test the water for phosphate and nitrate before you put in tank. If high - switch to RO.

If the water added to the tank is not the problem then cut back on feeding and if your using flake food stop that entirely (flake food is high in phosphate)

Water changes will help -

If you don't have a good skimmer - get one.

As you know a fuge is a good thing to have on any tank - even adding some macro to the tank will help.

Good luck.

 

[ufans]

Thanks for the reply....

I am using RO/DI water, but haven't tested the PO4 level of the product water yet... I will do that. I just figured that it would be filtered out. I also need to do a TDS test, but don't have a tester yet.

I think you are right about the flake food. I think that is the primary source of the PO4. Do you have another suggestion for food? I have pellets but not all of my inhabitants like that as much.

I have... 1xYellowTang, 2xMaroonClowns, 1xGobi, 3xShrimp, and numerous snails and hermit crabs.

My NO3 and NO2 are still at 0ppm so at least I have that going for me.

 

[Kevin1000]

The yellow tang will love some seaweed - purchase some nori (pressed dried seaweed - used in making sushi) from your local oriental market - you get about 10 large sheets of the stuff for about $1.50. Cut a thin strip of it and rubberband it to a small rock - once the fish starts to understand its food you can start to clip the nori to the side of the tank.

Clowns will eat about anything - try some frozen mysis shrimp & some frozen cyclop eeze. Mix in some spirolina for veggie.

Don't feed the shrimp, snails, and hemits - they get the left-overs only.

If you are using any kind of mechanical filtration make sure you clean the filter media often - any build up of debris on the filter material will add nitrate to your system. Run your skimmer at max capacity 24/7.

Hope this helps.

 

[randy holmes-farley]

It is certainly possible that you have phosphate on the sand. Even without that, you have too much in the water itself. I'd look to lower it, and growing macroalgae would be my preferred way. Using an iron-based phosphate binder is another good way, albeit more expensive.

This article details phosphate issues, including where it comes fom and how to export it:

Phosphorus: Algae’s Best Friend
http://www.advancedaquarist.com/issues/ ... 2/chem.htm

 

[ufans]

Thanks everyone for the good advice... I think i am going use everything...

I am in the process of adding a refugium to grow Caulerpa.

I am going to do a couple water changes to help get the PO4 level down fast.

I am going to remove all of the algae that I can see out of the tank

I am going to get some phosban as an added measure so I can use it when I get a rise later on.

I also setup a nori feeder for my yellow tang. I used a thermometer suction cup holder attached to a small piece of 3/4in vinyl tube that I wrapped the nori around with rubber bands. “Big Bird” loved the nori .

 

[randy holmes-farley]

Sounds good.

Good luck!