"Craig Brye" wrote in message ...
I take the simple method of measuring the parameters of my 29 gal. tank (130
watts of cf lighting and injected CO2) before I add chemicals. I then added
dry chemicals (for me it was a little over 1/4 teaspoon of KNO3, a small
pinch of PO4 [KH2PO4], and around 4-8mls of trace twice a week, and around
1/2 teaspoon of K2SO4 once a week) to the tank and do weekly water changes
of around 35-50% of the water. I then took measurements after adding
(usually about 6-12 hours later) the chemicals to see where the parameters
were (even if your tests aren't completely accurate, they should still
measure some increase in the corresponding chemicals in the tank). I took
in depth notes almost daily to see what was happening in the tank with
regards to plants and algae. I did this for a couple of months until I had
a pretty good routine down. Now I measure about 1-2 times a week to make
sure my parameters are in check.

--
Craig Brye
University of Phoenix Online

Cheers to Craig's advice.
Even if the 1/4 teaspoon measurement is off, or if the 1/4 teaspoon
you have is noit the same as mine, or you have a bit more than a level
teaspoon, per 1/4 teaspoon you might be off only about 1-2ppm of NO3.

If you are off 5ppm of K+ and in the range of 20-30ppm, it will not
make one hoot of difference.

1-2ppm of NO3 is not bad, few kits are that accurate anyway.

PO4 is similar to traces, as long as some is supplied every few
days(shoot for 3 with CO2 good lighting etc) the actual measurement
itself is not critical.

CO2 light and NO3 are the most critical elements that will burn you.

Simply adding enough of K, PO4 and traces is the other.

Even if you overdose, a weekly 50% water change removes the errors you
made dosing 1-2x mid week before you do another water change again.

In this manner you maintain a range of nutrients that neither runs out
nor builds up. You re set you tank's nutrients every week and dose by
guessing/approximating in between.

Main test is pH to determine CO2 content.

The others are tested to get a feel or when something is whacky.
Generally you don't even need to test pH is you have a good CO2 system
that stays fairly steady.

So even if Chuck's calcultor is off, does not account for grain sizes
and different brands of KNO3 etc, it is still a fairly robust method.

I add everything except traces dry to the tank.
Generally 3x a week or every 2-3 days. 50-70% weekly water change.

I use
Traces
K2SO4
KNO3
KH2PO4


Regards,
Tom Barr