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Re: adding PO4 & Fe
Jay Reeves <jbreeves at isd_net> wrotw:
> Subject: adding PO4 & Fe
> Does KH2PO4 = potassium phosphate? and what is H3PO4?
> I have a small jar of Sodium Phosphate, Tribasic can this be used to add
> P?
> Also have a LaMotte PO4 test kit to manage additions. Could someone
> offer some guideline to how to mix and dose PO4? i.e. 1t KH2PO4 + X amt
> water then dose about X ml per X gal. I have been a very happy camper
> since quitting the RO scene :-) thanks Tom and all! Plants really perk
> up after a water change now. Tap has 0.2 PO4 and I do a 50% water
> change. After water change PO4 is undetectable within 24 hrs. (probably
> less).
KH2PO4 = potassium phosphate, monobasic.
K2HPO4 = potassium phosphate, dibasic
K3PO4, or K3PO4 - H2O = patassium phosphate, tribasic
Check out the link about H3PO4, which is phosphoric acid. We
went through this last month. There's lots of replies to the initial
post.
http://www.actwin.com/fish/aquatic-plants/month.200104/msg00179.html
Yes, you can use sodium phosphate, but be aware; sodium
phosphate is Na3PO4 - 12H2O (dodecahydrate) mw 379.9 (25.00%
PO4). It's got lots of Na and water, and PO4 is what you're after.
Also, a 1% solution is pH 11.8-12.0, store out-of -reach. To figure
out how much to use and how much to dose, go to the chemistry
section of my website and run through the formulas; it's a lot easier
than requoting everything.
http://www.ais-gwd.com/~jjirons/chemistry.html
Heck, just change the water often and get free PO4!<g>
> another dosing question - how much TMG to add to a 75gal?
> KH from the tap is 2 - raised to 5 with baking soda. Have been trying
> to keep the nitrate close to 10 but forget or neglect for 1 - 2 days and
> it goes to <2. I had been following the suggested TMG dosage of about
> 10 - 15 ml / week for my size tank / water hardness. Using a LaMotte FE
> test kit readings were always well below 0.10. Recently have increased
> dosage to as much as 45 ml / week. Is this excessive? Readings are
> still within reason <0.10 and the plants are looking much better.
The bottle states 5ml / 50L, which is 5ml per 13.2 gals, or in your
case, 28.4 mls for 75 gals (water column). Probably a little less
depending on how much water is in your column. Your 10-15 mls /
week probably wasn't enough. 45ml may be excessive. The bottle
also states that soft water folks should use less, anyway.
Also, you said you missed a couple of days of dosing what,
KNO3?, and your nitrates fell to zero. TMG doesn't contain NO3 or
PO4. Hopefully that wasn't what you were referring to ;-).
Jamie <"\\\>< Aquatic plants, water chemistry, and cichlids
Greenwood, SC http://www.ais-gwd.com/~jjirons