PH Rising

[ricardo48]

My PH is steadily rising... at the beginning of the week it was 7.3 and now its 7.6.


I have diy co2 but changed the bottle a day ago when my PH was 7.5 but it has not lowered it.

My outgassed aquarium water is 8.3 so I am aiming for a PH of 7.3

The strange thing is my drop checker is lime green/yellow still even though going by my PH/KH I have barely 15ppm of co2 at the moment.

I am using 4dkh solution accurate to 0.01 ppm and my co2 diffusion is into external reactor which in turn goes into inlet of canister filter which in turn has the out put going into a powerhead so any burped out co2 is misted into the tank.


Any ideas why my PH is going up yet drop checker is still looking good? Should I just disregard the PH?

[fort384]

pH/KH may not be a good way in your tank to measure co2. It sounds like your water has a lot of buffers in it being your pH is so high. Since your are using a drop checker with calibrated 4dKH solution in it, I would be more apt to trust it than a straight up pH KH measurement given the naturally high pH of your tank. If your drop checker is indicating yello, you may want to actually decrease co2 input a bit to get it back to green. Higher is better than low though for controlling algae (so long as it doesn't go over 80~100 ppm, which would be dangerous for fish). Some sites say over 30 is dangerous but I have kept my tank at 50+ before with no adverse effect on livestock.

[ricardo48]

didnt think i had any buffers in my tank except P04 which i dose to 2ppm

[jsoong]

Originally Posted by ricardo48

didnt think i had any buffers in my tank except P04 which i dose to 2ppm

You don't have to be adding the buffers, the buffers might have been in the water to start with ....

To validate the pH/KH/CO2 relationship, you can take some tap water, let it aerate & equilibrate with room air for 24 hrs., then measure the KH & pH. If the calculated CO2 is not 3 or 4 (atmospheric CO2), then you have additional buffers in the water ... either naturally occuring, added by your water co, or yourself.

At any rate, the drop checker is the more accurate way to measure CO2, i would trust that more than the pH/KH calculation. <Which is only valid in pure water with only bicarbonates as buffer.>

[fort384]

Why do you think that? I would think there is a lot there being that your pH starts as high as it does with your tap water.

[ricardo48]

My degassed aquarium water comes out as 8.3

My aqurium Ph is now 7.3.

So a whole 1 point drop would confirm 30ppm co2? Drop checker is also lime green.