Phosphate issues!

JurisHP · 06/16/2020, 06:05 AM

I have always battled high phosphates---I use RODI water exclusively, and have tried various methods of reduction (GFO for a couple of years until I recently replaced that with Phosguard).

I first added the Phosguard to my sump in a filter pouch with the recommended amount. After 1 week, my levels were STILl at .90 (HannaChecker).

So I decided to double-up and put another pouch---4 days later (today) STILL .90!!

Any suggestions?

REALLY annoying/frustrating!

Michael Hoaster · 06/16/2020, 06:36 AM

Usually the biggest source of phosphate in aquariums is fish food. I'd suggest looking at the amount of food you are adding. Lot's of people overfeed. Consider adding a Nassarius snail or two to clean up any extra food. Macro algae take up phosphate. More water changes could help. Maybe a better skimmer.

I've read that dry rock can leach phosphate for a year or more. Since it sounds like this has been a problem for 2+ years, I tend to come back to overfeeding as the likely culprit. You may also want to test your ro/di water just to be sure it isn't the source.

That's all I can think of. Good luck with it!

bertoni · 06/16/2020, 07:37 PM

I agree that fish food is the most likely source of phosphate. If the level has been high for long, leaching can be a major concern. The media might be exhausted in a few hours with the level at 0.9 ppm. Also, the media needs to have water forced through it to be effective. That's generally easier in a reactor.

For larger tanks, lanthanum dosing (SeaKlear and the like) can be cheaper than media like PhosGuard. How big is this system?

06/16/2020, 06:05 AM	#1
JurisHP Registered Member Join Date: Sep 2008 Location: Philadelphia, PA Posts: 168	Phosphate issues! I have always battled high phosphates---I use RODI water exclusively, and have tried various methods of reduction (GFO for a couple of years until I recently replaced that with Phosguard). I first added the Phosguard to my sump in a filter pouch with the recommended amount. After 1 week, my levels were STILl at .90 (HannaChecker). So I decided to double-up and put another pouch---4 days later (today) STILL .90!! Any suggestions? REALLY annoying/frustrating!

06/16/2020, 06:36 AM	#2
Michael Hoaster Registered Seaweedist Join Date: Feb 2004 Location: Boulder, CO Posts: 5,807	Usually the biggest source of phosphate in aquariums is fish food. I'd suggest looking at the amount of food you are adding. Lot's of people overfeed. Consider adding a Nassarius snail or two to clean up any extra food. Macro algae take up phosphate. More water changes could help. Maybe a better skimmer. I've read that dry rock can leach phosphate for a year or more. Since it sounds like this has been a problem for 2+ years, I tend to come back to overfeeding as the likely culprit. You may also want to test your ro/di water just to be sure it isn't the source. That's all I can think of. Good luck with it! __________________ As many naturalists and environmentalists have suggested, we should set aside our arrogance, our desire to conquer and control everything, and walk hand in hand with Mother Nature. -Walter Adey Current Tank Info: 180g Seagrass Sandbar Lagoon, START DATE November 28, 2018 Last edited by Michael Hoaster; 06/16/2020 at 07:52 PM.

06/16/2020, 07:37 PM	#3
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	I agree that fish food is the most likely source of phosphate. If the level has been high for long, leaching can be a major concern. The media might be exhausted in a few hours with the level at 0.9 ppm. Also, the media needs to have water forced through it to be effective. That's generally easier in a reactor. For larger tanks, lanthanum dosing (SeaKlear and the like) can be cheaper than media like PhosGuard. How big is this system? __________________ Jonathan Bertoni