P04 in effluent

[MidTnMike41]

I am using a Hanna UL Phosphorus checker and i am constantly getting higher readings out of my GFO effluent than I am my tank. I have tried changing GFO then testing but it comes out the same almost every time. I am constantly getting 3-5 (.02) in my display tank and in the 20's (0.06-0.07) out of the GFO effluent. I usually test back to back, and have tried DT first then GFO second, and even switched them, same results. Any ideas what would cause this?

 

[CStrickland]

Maybe the effluent has particles or crud from bacteria in it?
I know for the Hanna you have make sure the tube is really clean, so perhaps cloudy water would upset the meter too. You could try collecting the water in a cup, letting it settle for 20 minutes, and then pouring off into the tester tube.

 

[MidTnMike41]

After letting the effluent water settle in a cup for 30 min, I tested again and got a 4, which is the same as my display tank. The GFO is only a few days old, I am going to test again in a few days. I would hope that its not exhausted already. I might need to slow the flow through the reactor a little as well. I have a little more tumble than I probably should. It is in a dual reactor.

 

[MidTnMike41]

I am not sure which one caused the issue but after letting it sit for about 15 min and letting RO water sit in the vials between uses I am getting 0 in the tank and 0 in the effluent now. I have been changing out GFO almost every week for a few months because I thought my phosphates were creeping up. Thanks for your help!

 

[CStrickland]

Yay! :thumbsup: