Backyard Aquaponics
A place to discuss aquaponics

My PH is staying right around 7.4...down from 7.6 a year ago. It looks like I need to supplement, but not sure what to use that won't raise my PH even higher. Any suggestions? This would be so easy in a dirt garden. SuperPhosphate- 0-45-0 and done.

What is your phosphorus reading? I still believe phosphorus is the most abundant mineral found in AP and find it odd that systems have deficiencies there. But in answer to your question Id go for a foliar feed of M.P.K

There are a bunch of threads with discussion about phosphorus.

I think he meant to say N.P.K. typos are a hell of a ting.

Not sure...in the process of ordering a test kit for P. Just looking at my plants and descriptions/photos, that's what it looks like. What is MPK? Do you mean N.P.K.? as in Nitrogen, Phosphorus, and Potassium?

I don't know of any organic complete fertilizers that are high in P. My background is commercial horticulture...this organic and fish safe stuff is all new to me.

MonoPotassium Phosphate (MPK)

What charlie said. I use MKP (MonoPotassium Phosphate). Gives a bit of a potassium boost as well, which is almost always needed.

Whoops, yes sorry I had the K and the P around the wrong way. Thanks Matty.

I use Blood and Bone in my system, I've posted the analysis before, probably in my thread and maybe another about P supplementation as well.

oh thanks for clearing the up... is that similar to T.S.P....?