Brand New GFO - Effluent Phosphate Positive

[ReefHunter006]

What am I doing wrong? GFO has been in the reactor for 20 mins. 150g of rowahos in a mini brs reactor on 240 gallons. It is tumbling so gently and flow is reduced that only a few small areas of it tumble.

Took an effulent reading and confirmed it with salifert. Extact sam as tank water between .7-1ppm.

 

[Randy Holmes-Farley Verified Community Expert]

Not sure what the issue is. Could be the water is channeling through it, the test is off, the GFO is already depleted, etc.

 

[ReefHunter006]

If it is channeling through, I am not sure what I can do to prevent it.

I have confirmed testing with a third test kit.

20 mins with only 50-100gph running through the reactor seems very quick, no?

 

[Randy Holmes-Farley Verified Community Expert]

100 gph might be too high to easily detect. Maybe it is too fast to reliably detect the drop by test kit. The residence time must only be a few seconds. You will not get more binding by going slower, but might see it easier.

Can you drop that rate a lot and retest?

 

[ReefHunter006]

I washed a new batch and tested within the first 5 mins and it ready .4ppm. Tank is .7ppm. I slowed the flow down to the point it stopped tumbling.

 

[Randy Holmes-Farley Verified Community Expert]

That’s reasonable. :)