Originally Posted by Markharrislondoncanada
Though I assume that it's not recommended, would I be able to test the influence of the HOB filter by shutting it off overnight? If surface agitation is a main culprit, and if I shut the filter off, would pH be expected to drop after just one 12 hour "night" period?
I will look into finding a drop checker. But is the ph-KH relationship (through pH and KH test kits) completely unreliable? Shouldn't I still see some kind of pH change, but just not be able to rely on the test kits for an "accurate" calculation of CO2?
In other words, if I eliminate the HOB, I should see better gas dissolution/distribution. And if I get a drop checker, I should be able to more accurate estimate the concentration.
What is the experation date on your Ph solution... maybe its out of date. Also instead of removing your HoB why not just remove the wheel part,keep it in a bucket of water so the bacteria doesn't die. I think it would be to harmful to keep the filter off overnight since the bacteria need oxygen to live too.
I use to have the ladder difuser in my 37 gallon and I had noticable co2 levels something is wrong. (seeing ph drop) and I also had a KH of around 10.
Also, do you see any pearling/ O2 being released by the plants that is also another sign that Co2 is actually in the water column.
ps, you can get a drop checker for 3-10 dollars shipped from evilbay. They also have packages available that come with 4dkh solution, there is also a seller that is selling them here on plantedtank but is a US seller.