New help with co2

[philipraposo1982]

I got my new co2 all set up and I have been doing a fair bit of reading about it but there is still something I don't quite understand.

Here is what I do know:
- a low working pressure making fine turning through the needle valve easier and saved on gas ( a little)
- 30ppm is pretty much the goal to reach
- too much gas can suffocate the fish
- should run co2 an hour or two before lights come on, turn off co2 about an hour before lights go out.

So here is where I need some help. I understand I want to drop about 1 point of ph to achieve my desired co2 levels (to provide an non limiting amount of co2). I was reading and have been told that the drop of co2 ideally would be fairly quick (within an hour or so) and then would level off and remain at that ph for the rest of the day.

What I don't understand is how is it possible to drop the ph that quickly and then have it level off without constantly adjusting the co2? I don't have a ph controller, I am assuming maybe I need one to achieve this goal?

Is it okay if my ph drop of one paint take several hours instead of just 1? Lets say 3-4 hours to drop 1 point of ph, is that okay?

If I never see my fish gasping and they still seems active and normal is it safe to assume the co2 levels are safe and not hurting them?

finally, how much surface agitation if any do I want / need for the tank?

thanks in advanced for any advice / help.

 

[tim]

Ph drop off 1 will occur then plant uptake should make it level off and remain stable, starting earlier at a lower rate shouldn't cause problems IMO I have mine on 4hours before lights and off 2 hours before lights off, Co2 is a fine balance and better to start slower for longer IMO for the sake of livestock, surface agitation should be a nice ripple without splashing for good gas exchange, be aware though if you have surface film/scum the excess co2 won't dissipate and levels can become harmful fairly quick, the use of a surface skimmer like the ehiem 350 can solve this as I don't believe all surface film is caused by unhealthy plants, hope that helps.

 

[philipraposo1982]

In the past I have always had good surface ripple without breaking the water. Since co2 has been running I haven't changed things in that respect. I will continue to have a good ripple and see how that goes.

I guess that makes sense; drop to the desired level of co2 and rely on the plants to use a certain amount in order to maintain the desired level through the day when lights are on. But what if you have a tank full of plants that grow slower than stems? Like anubias and ferns, crypts and such? My guess is that you wouldn't need as much co2 because they won't be able to use it up as fast as let's say more stem plants that grow like crazy.
Right?

 

[tim]

That's correct a tank full of slow growers like those mentioned above may not even need co2 under the correct light intensity, make small adjustments to your co2 until you feel you have it dialled in for the the plants needs and the livestock would be my recommendation, ensuring you are around to watch the livestock with each increase.

 

[Andy Thurston]

I don't believe all surface film is caused by unhealthy plants

me neither but in my tank if I dont add enough ferts then I get more surface film.