Re: KH2PO4 etc

[Thomas Barr <tcbiii at earthlink_net>]

>> I ordered some KH2PO4 (monopotassium phosphate - one K, two H's), and have
>> recently started to add it ( together with K, N) to some of my tanks.
> 
> Where did you order from.

Fisher Chemical or www.litemanu.com
You can use Fleet enemas also(mostly PO4) from the local drug store.
Add a drop per 10 gallons 2x a week or so.
Or a rice grain's or two's worth 2 x a week per 20 gallons.
 
>> BTW, when I add K and N with the P, here is my formula for 100 gallons:
>> 1/4 tsp of calcium nitrate (1.5gms)
>> 1/4 tsp potassium nitrate (1.4gms)
>> 1 test kit measure of monopotassium phosphate (.03g)
> 
> What is a test kit measure?

A dinky little spoon of a known volume.

> What do you test for?

PO4.

> And what should be the test range?

Don't know, I keep mine in the .5 to 1.0ppm  range.
At or less than .2ppm or .3ppm seems to slow plant growth down in some cases
depending on test kit quality and other nutrients.

> Or is it all just visible signs of nutrient deficiency?

You don't see deficiencies really with PO4 limitation. You do see slowed
notable NO3 uptake. That likely extends to most other nutrients and also O2
produce for sure.
Plant pearl like mad after adding it if the tank has good CO2, NO3, K and
traces.

Regards, 
Tom Barr
  
> Thank you
> 
> Steve