Hi,
post yet talking about how to dose co2 despite the fact i read lots of them
Have you looked in the c02 forum section?
There are zillions of threads on how to diffuse c02.
How are you doing it now?
A DC is a good tool, just note that it has limitations.
I think it is one of the better tools out there to help gain experience. They are relatively easy to use and not that expensive. I and others have used more than 1 at times, so they can be positioned at different spots in the tank.
As far as dosing goes, you can watch the FISH and INVERTS for immediate signs/clues of too much c02.
SLOWLY increase the bubble rate a bit every few days. Watch the fish for signs of stress:
1. Gasping at surface.
2. Darkening of colors
3. Rapid gill movement
4. Dis-coloration
5. Hiding abnormally
6. General listlessness
If you see ANY of these signs, turn the c02 down and agitate the surface.
Adding some surface ripple via a small powerhead can also aid the fish.
Once you have hit where the fish or inverts are adversely affected, you know you have too much c02.
Back it down and go from there. You now have an UPPER LIMIT. If all critters are okay, try raising again.
Do not increase c02 and take off for several hours or the day.
We have all seen effects days after the change.
It may take the PLANTS 1-3 weeks before they really start to respond.
You may also need to increase EI as the carbon will make the plants assimilate better.
Remember that how you inject c02 is important as well. Any component in that configuration will have an effect.
For instance using your filter to drive c02 will be impaced as the filter clogs.
Does this help at all?