Water Chemistry Question

I have spent the day blitzing my tanks, cleaning everything, and testing the water for various bits and pieces. Here's the results -

ph - 7.5

GH - 12

KH - 4

O2 - 8.0 (recommended 8.3)

CO2 - 4 (lower than recommended 5 - 9)

Goldies Tank

ph - 7.5 - 7.8

GH - 10

KH - 4

O2 - 8 - 11 (ok for tank with tyemp of 23)

CO2 - 4 (lower than recommended 5 - 9)


Ammonia etc are all as they should be..

So, my question is, do I need to do anything about the o2 and co2 levels? I have had 2 fish die lately. Both had lost almost all their colouration which apparently can be caused by low oxygen levels. To try and correct this I keep the bubbles on more and have put a spray bar in so I can cause more water disturbance without the fish being blasted about..

Would it be worth adding more than the recommended dose of Seachem organic CO2 or would that do more harm than good?

I dont know the answer I am afraid Diana, but do you have to check for all these things regularly? I have a test kit for ammonia, nitrite and nitrate but not GH and KH (whatever that is), so do I need to get some of that too? I never thought that you would have to check for oxygen either but I guess thats important isnt it?

Well the CO2 is mainly of interest to the plants, I would've thought... Plus if you increase that, it might just deplete the O2 levels even further.

I'm more interested in your KH which at 4, is right on the cusp for a pH crash... ...I'd test that once a week at least and if it drops any lower, you should buffer it with Sodium Bicarbonate i.e. Baking Soda (NB not Baking Powder) which you can buy from the baking section in your local supermarket. I have to do this at least once a month with my tanks as the KH fluctuates quite a bit.

Thanks for that info Mary, I was hoping you would come on and notice it .

I didnt know that the KH level was a bit dodgy, what are the acceptable levels for this (the test kit doesnt tell you believe it or not. I will test for it weekly.

Watch out for further questions!!

Diana wrote:

I didnt know that the KH level was a bit dodgy, what are the acceptable levels for this (the test kit doesnt tell you believe it or not. I will test for it weekly.

4 or higher. When I started to test mine, it had dropped to 1...

Test the pH at the same time 'coz the two values are linked. You can read more about it in my fab. article in the Water Chemistry section.

Goof plug you got in there Mary!

I never check for any of thius stuff and am beginning to think I am doing things wrong. I knew it was all just TOOOOO easy!

Well if your water is soft (my GH is only 6), it's a good idea to keep an eye on it. Case in point: my KH was only 2 today... ...so out came the sodium bicarbonate...again! Anyway, I love messing about with testtubes and stuff...

Going to test everything today so am having a day with my white coat and Bunsen Burner