DIY CO2 monitoring?

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

rcherry

Aquarium Advice Activist
Joined
Feb 6, 2011
Messages
113
I have a small planted mbuna cichlid tank (just a 29G with a couple of fish in it). I keep the cichlids well fed with multiple small feedings so theyve mostly been ignoring my plants. I have some vallisneria, some java fern and moss, and some anubias and I would like to give them a healthier environment. I'm building a DIY CO2 delivery system, but my question is how do I know when the CO2 hits about 25ppm? My pH is about 8 to 8.2 with my DKH at about 12 (before any CO2 injection) and I can't figure out how to extrapolate my CO2 measurement from these numbers. Also, would I need to fertilize in unison with the CO2 to notice any real growth, or would the CO2 alone provide an increase in growth? I have about 1.5ish WPG of t5 light, which should be enough for these low to low medium light plants. Thanks for any help.
 
Check out this thread:
http://www.aquariumadvice.com/forums/f20/1-4-diy-3-4-purchased-co2-system-136350.html
It will tell you all about how to build a DIY CO2 reactor, and on page 2 it explains how to measure CO2 in a planted tank.

Whether or not you need fertilizer depends on many factors... I can't tell you for sure if you do or do not need it... but for low light plants with lower lighting, it is usually not a requirement.
 
Thanks for the quick answer, but the chart on page 2 only goes up to a pH of 8, and on that chart the ppm of CO2 never goes above 6 or so for a pH of 8. It has to be possible to inject enough CO2 to get the ppm up to 20 in such basic water, I just want to make sure I don't overshoot my target area. Is there any other way to monitor the CO2 levels, particularly for a tank with a high pH?
 
CO2 = 3 * KH * 10^(7-pH)

KH is in degrees. This will give you co2 in ppm.

If you have a bunch of co3 buffers coming from the tap, this formula will not work for your tank.

However if you get a drop checker and use a KH standard of 4d KH it will read accurately because it will remove your tank water with unknown buffers as a variable.
 
Last edited:
^yes. a drop checker is the solution! I tried the pH kH thing and it just didn't work for me. I struggled. Drop checker just requires you to look and see blue/green/yellow. Much much easier, and only maybe $15 when it's all said and done.
 
Thanks a lot guys, I appreciate it. Is there a DIY method to building a drop checker or should I find one on eBay or somewhere?
 
Back
Top Bottom