pepetj

Hi fishlorians!

I finally got my hands on a real dissolved CO2 test kit. It's manufactured by HACH and works quite nicely. I've been using DIY drop checkers to estimate the
levels of dissolved CO2 (error of measurement 36%, as I recall). The pH/KH charts are quite inaccurate (a marketing trick by Tetra in its otherwise good Laborett test kit).

It works using a tritation method that can be graded as low range (1.25 to 25ppm), mid range (2-40ppm) and high range (5-100ppm).

It comes with a graded acrylic bottle (marked at 10, 15, 20 and 23ml) a test vial (also acrylic) and two reagents. Reagent 1 is a 1% solution of Phenolphthalein and Regent 2 a 0.01% standard solution of Sodium Hydroxide. These reagents should be stored at a somewhat stringent temperature range (within 10 to 25C = 50 to 77F) or the accuracy of readings could be compromised.


http://www.aquamerik.com/catalogue/p...ysehach&lg=eng

I have got readings as follows: at noon-early evening time 12ppm. Late at night 24ppm. This makes sense as the plants use CO2 with lights on but produce it while off.

Once I upgrade to pressurized (I'm close to make the move) it will be easier for me to adjust CO2 injection.

Pepetj
Santo Domingo