Live Rock Retaining Phosphates?

[designsonline.co.uk]

Hi My LFS has told me that the reason I am having a problem with lowering my phosphate level is that I have so much live rock as live rock retains phosphates, even if you do a 100% water change!

This sounds wrong to me, but then what do I know....

If this is right, is there any way of treating the rock, rather than just treating the water? Is there a really serious treatment that can be done to eliminate phosphates? (Other than buying new live rock and fresh water...?)

I really need to get this sorted out now as I am starting to get a green algae on the glass and rocks etc...

(phosphate levels are about 2.8 !)

Joe

[kim]

Yes, it's true. LR, coral sand....anything made of aragonite is a good adsorber of phosphates. Especially if the pH changes (rises or falls) these can then be released back into the water.

Even so, your measurement suggests something else wrong in addition.

Assuming that you are using a phosphate adsorber, and it isn't exhausted, phosphates shouldn't be that high. The adsorber will remove the phosphates as fast as they leach, it should therefore measure close to zero. You'd probably still get algae until the rock was finally cleared of phosphates, but you wouldn't get readings that high.

Adsorption of phosphates onto rock etc. is one reason it's so important to keep phosphates low at all times....if you let them build up, they will be a bore to remove.

But suggest you recheck the results, and of course, until the stuff clears, keep on replacing the adsorber whenever you see significant phosphates in the water (eg, as an idea, maybe 0.25 ppm....what do people use as a key ? ).

Also check your freshwater, even if it is RO/DI/NASA approved.....

kim

[designsonline.co.uk]

I have just bought a big tub of Rowaphos, and 2 water syphons with the wide tubes, I cut several round pieces of filter media and shoved them down to the end filled the tube with rowaphos, shoved the other peices of filter media in after the Rowaphos, and connected another syphon tube end connector to the other end and plugged a power head in to the end tube, after collecting all the red water in a bucket and making sure that the water was running clear I have installed it in the tank, so I now have a home made fluidised phosphate reactor, with 250 ml of Rowaphos in it, I have been told this will likely reduce my phosphates to 0 in under 2 weeks.
What so people think....?

Joe

[kim]

I believe that Rowaphos tells you how many ppm it will remove (in ideal conditions), so given how severe the ppm, I'd check to see whether a water change would also help (might be cheaper).

[designsonline.co.uk]

It seems to be working really well, the water in the tank is now down to 0.5 phosphate, and the water coming out of the reactor is 0

I am really realy pleased with this, how often will I need to change the Rowaphos do you think?

Joe

[weegaz22]

id say change it when the water coming from the reactor is no longer 0 ;)

[Reefworks]

In a reef system phosphate levels should be kept bellow 0.03 ppm, above this level calcification is inhibited, algae growth is also quicker at levels even lower than this. This is quite interesting as many packet phosphate tests kits claim to be for marine systems but only test down to 0.1 ppm. :wacko:
Not in any way saying that one phosphate remover is more effective than another but I think that the amount of phosphate that a 500ml tub of rowaphos will remove from seawater is 3ppm in 1,000 litres, you will have to check that though as its off the top of my head.

[bigbok]

YOUR RIGHT in thinking that the rock will absorb the phosphates and leach them back out as for your ingenious idea is the rowa phos clumped at one end or circulating throughout the tube if it the first then it is a filter you have made and would be better off putting anti phos in if it is fluidising then great what are you testing the phosphates with ???