I read somewhere about when looking for a P04 test kit that I do not want a kit that measures total phosphates but one that measures ortho phosphates.

Correct me if I am wrong please.

I purchased a Nutrafin P04 test kit but can't find anything on it about ortho compared to total phosphate. Can anybody tell me anything about this?

Also, my tape water measures 1.0 P04. My tank before water change was 5.0 P04 which is the max for this test kit. After a 50% water change it measures just over 2.5 P04. Should I still be dosing KH2P04?

I dose E.I. for 25 gallons water in a 29 gallon tank:
1/4 tsp KN03 3 X a week
1/8 tsp K2S04 3 X a week
1/16 tsp KH2P04 3 X a week
on off days:
1/8 tsp CSM+B 3 X a week
1/16 tsp FE (chalated) 3 X a week
Also on water change day I add 1/2 tsp Grumpy's GH booster for the added nutrients etc.

Mid week my paramters are:
P04 - 5.0
KH - 180
GH - 300
PH - 6.6 to 6.8 (mid day)
NH3 - 0
N02 - 0
N03 - 40

Tap Water:
PH 7.2
Nitrate according to the city's water report is .16
Phosphate according to the city's water report is 1.5

I have a heavy fish load and heavy plant load. Pressurized C02 @ 2 bps, Drop checker is green to yellow green. Lights, 130 watts CF, 6700k. I have good water circulation and surface movement. Water temp 76 degrees.

Can anybody examine and recommend anything on this?

Thank you so much.

Joe