You've probably got a lot of phosphate bound to your rocks and sand. Three or four years ago when I first tested my tank for it I was at .75. So then I started to do all of those things that I listed earlier including running 2 cups of GFO that I changed once or twice a month. At first I used rowaphos because it was readily available but then I switched to BRS GFO and even a container of HC GFO to keep my costs down. Eventually I drew it all out of my system and now I only need 1 cup that I change every two months to maintain it at an undetectable level. Macro algae no longer grows for me, I have no more bryopsis, and my glass only needs to be cleaned once a week.

Old tank syndrome where the rocks and sand start releasing their bound up Phosphate has also been cured by using Foz Down.

I recently took over maintenance on a 240 gallon system with large fish that had been heavily fed for over 5 years. The Phosphate read 1.41mg/l on a Lamotte Smart 2 Colorimeter. After 2 weeks the Phosphate is now under control with the routine addition of small amounts of Foz Down via Profilux doser. The cost to do this was about $75 in Foz Down and 4 x 15% water changes. Time to start putting the SPS in. :)

Two weeks, WOW, my concern is dropping it that fast. It might seriously shock my corals to much. But i guess I would just add smaller amounts???? Hmmm gotta do more reading. Do you have info on your website about it?

The tank had mainly paly's and shroomz and a gorg with a few LPS, Fox Coral, Pearl Bubble and a Blasto pipe. They all did fine.

From my own system you can drop Phosphate by .25 per 48hrs with out any issues for SPS. Had a bad shipment of Trochus once :-(

Here is the link to the site http://www.oceanfreshaquarium.com/foz-down/
Cheers,
Tim

Thanks for the link TIM, yeah I will give it a go. And it just so happens I know where I can get my hands on a bottle. Thanks again. I will keep this thread going with my results from using it, then maybe it will help others.
:0)

Thanks Ronnie. I am sure you will find the product very effective.

Cheers,
Tim

I have been playing around with Brightwell Aquatics XPort PO4, which is kind of like a crouton version of GFO, but 'ultra' high capacity and not requiring fluidizing. I am down to using half the recommended dose of the same amount of HC GFO and after a couple of months am still getting Hannah PO4 readings near 0.00-0.03 with daily feedings of Reef Snow, various other (non-rinsed) foods for the fish and periodically coral frenzy and reef roids (very high in PO4) and ATO with RODI.
In terms of food rinsing, Randy HF recently wrote an article that covered sources of PO4 in the aquarium and concluded PO4 sourced from most (or maybe all) frozen foods were the major contributor to PO4 but rinsing did NOT reduce PO4 by any significant amount: http://www.advancedaquarist.com/2012/3/chemistry.
I am happy with the XPort PO4 product but don't see why using more GFO wouldn't accomplish the same goal. I have some extra if anyone around Nanaimo would like to give it a try.
Dan

So if you dose into your overflow and it goes almost immediately into a filter sock... is the foz down still as effective? And will a 200 micron sock catch the precipitate? I'd imagine that not all of the foz down would react right away and it would get through the sock itself and cause precipitation elsewhere where you can't collect it?

I have an unused doser channel so I'm curious...

If you have phosphate issues, it is most likely caused by something YOU are doing.

Most likely overfeeding or lack of maintenance. I know, you are not "over feeding"... nobody ever does. :twised:

Try reducing feeding amounts a little. 25% max at first.

Try more water changes as well.

Adding GFO or anything else is not a solution.

Before dropping money on yet another product to dose your tank with, just try the due diligence. Trust me, you do not need a phos remover in most cases. I did aquarium maintenance for some time, and what I am saying, will work, as I have taken many client tanks from high to low readings.

Once you get it under control manually, you can use GFO or pellets to help maintain.

EVEN if you did just go GFO or something, it is going to take time. Possibly 1-2 months as if you do not change the activity causing the PO4, you are simply fighting it, not controlling.

1) 25% water change - this weekend and again next.
2) reduce feeding up to 25% - watch the fish... if they get skinny, you have gone to far, but generally not going to happen
3) after levels are reduced, use PO4 controlling substance to help keep levels down.

Good luck.

Oh yea... Forgot to add, this way is free. If you do not get results, you are not any further behind.

Patrick