I have finally got my c02 set up working properly and got the following results

Morning ph 7.2, kh 9
Evening ph 7.2, kh 8

Looks like I am getting about 2ppm drop in a day, should I add more? flow is about 1 bubble every 2 secs atm
Tap ph is 7.6 and kh is around 9

thanks


Paul

Why would your Kh change overnight? If anything the Ph should change.

http://www.aquatic-plants.org/articl...hph_table.html


Add enough CO2 to get a pH of no less than 7.4, use only CO2 to do this.
Keep it there when the lights are on.

Regards,
Tom Barr

I dont know, last time I checked it the same thing happened, dont know if its crappy test kits, we can only get api or hagen ones here normally, I have seen the guys in the usa use better ones, I am struggling to find them in the uk

I think tom made a mistake... The pH should be kept between 6.9-7.0 during the photoperiod.

Regards
Peter Gwee

so do i add a little more c02? or is it ok, I am happy with this, swords have flower stem about to reach the surface and all looks good
tap ph is 7.6, I m mixing 50/50 with ro

Paul, it really depends on how much light you have over your tank. At lower light levels, it will not be that critical but at 30ppm, nothing will be limited.

Regards
Peter Gwee

sorry, should have said, I have 60 watts and its a 120L tank, an arcadia original an a marine wite tube in there atm

Is this CO2 table wrong? http://www.aquatic-plants.org/articl...hph_table.html

According to my table and others if you have a pH of 7.0 and your KH is 10 the CO2 should be 30 but on this table it is 76.

Yes it does seem wrong, doesn't it?

At a KH of 9 and a pH of 7.0 the CO2 will be at 31.7mg/l (at 25 degrees C).

That's what I would aim for...