In article _PJra.672813$3D1.374077@sccrnsc01, Alex R
writes
As long as you're buying new test kits, get a phosphate kit as well.
With your lighting, it's likely that there is not enough PO4 in your
tank. And I doubt your PMDD mixture has any potassium phosphate. Plants
need PO4 as much as other macronutrients. It might be a little
difficult to find KH2PO4,
though.

OK thanx for the idea. Any idea what contains PO4 ?

--
Alan Silver
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