[plantsplantsplants]

Hello guys, six-month old lurker here. I've been reading a lot about how one goes about calibrating their CO2 and see mainly three ways mentioned: 1) drop checker (discouraged by most members); 2) pH drop method; 3) manual adjustment and observe livestock/plants.

While I have had my tank set up for a good six months now and plants seem to be doing well, I have a question on the pH drop method. For some reason my water's pH is really low at 4.8 before CO2 comes on (tested with pen and test kit, dkH is 3. I use ADA amazonia soil and can only think of this as the sole reason for low pH). While I am aware in most cases people aim for a 1pH drop with dkH in range of 1-10, I am curious to know what I should aim for given my already low starting pH. I have read in multiply threads that the lower the pH is, the larger the CO2 changes in PPM per 0.1 drop in pH. Right now my pH saturates at around 4.4 making it a 0.4 drop just 30min - 1 hour after the lights come on.

Any advice would be appreciated and thank you for all the great content available here!

 

[moke]

don't think it's the 6 month old aquasoil. perhaps you do not have enough surface agitation. co2 is not being out gassed efficiently enough. take out a sample of your water before co2 comes on. test pH. 24 hours later, test it again. if the pH is higher, which i suspect, you need to increase surface agitation. you really want to see a 1 pt pH drop by the time the lights come on and have it remain steady throughout the photoperiod. it's a balance between co2 input and that which is used by plants, and that which is off gassed.