How Much CO2 to Start with in a 90 Gallon Planted Tank

[WhiteCloud]

I finally got my CO2 tanks (and filled it today), JBJ Regulator and SMS 122 pH Monitor, and Plant Guild Reactor

I am ready to set this baby up...but then I realized...I have no idea how much I should be adding or starting with:

1. How many "bubbles" do I start with?
2. How fast can I drop the pH in the tank without endangering the occupants
3. When will the plants be getting some benefit from CO2?
4. How many bubbles do most people add to the tank?

Thanks

WC

 

[SnyperP]

I don't have pressurized co2, but i think they benifit from any extra co2 in the tank. =p

 

[malkore]

Well, what's your carbonate hardness, in ppm or dKh? Gotta make sure you have enough to safely inject CO2 first.

Assuming you have at least 3 dKh, start with 15 bubbles per minute (bpm) and run 24 hours, then test and see what your CO2 levels are at.

as for your #4 question, this isn't useful information, as your particular water chemistry and diffusing method will greatly affect your CO2 levels. bubble rate only tells you how much CO2 you're trying to push into the tank...you must test to know how much is actually dissolving into the water column.

 

[WhiteCloud]

KH=6

So I am in the safe zone to use CO2...at least I hope so!

I started it at 30 bubbles per minute (1/2 bubble per second) to start. I set the pH meter to 7.6 so it would bring the pH from 7.8 slowly. Now 6 hours later...I am at 7.6 and the regulator turned off just like it is supposed to...neat!

I am thinking about turning down the pH slowly (0.1-0.2 per day) until I get to my desired 7.2. I am guessing that the lower I set the pH, I may have to increase the bubbles per minute to maintain that pH....but it seems fine for now. Should be less stressful to the fish if I take it down slowly. So far, no stress has been seen..and the boys ate ravenously as always.

It is time for "lights out"..no CO2 will be utilized until the morning. I am hoping I don't get a pH crash or anything over the night...it may be a little tough sleeping tonight!

Wish me luck!

WC

 

[TankGirl]

Test your water right before lights out and right before lights on in the AM, and see what the difference is. That will tell you what is going on overnight and you can decide if the swing is too great. You could leave the CO2 running and put an airstone on a timer to come on only after lights out as an alternative. Test it and see which is the better option.

Fingers totally crossed that hubby is getting me a pressurized system for Christmas, so I'll be the one asking for hand-holding in the next week or two, hopefully...

 

[WhiteCloud]

Tankgirl....I can't believe that your planted tanks in your gallery do not have a pressurized CO2 delivery yet!!! They are wonderful without one...can't wait to see pictures of you tank after "Santa" comes (Hope you've been a good girl this year!)

I have the SMS122 pH monitor...so I see 7.6 now...I hope I see 7.6 in the morning. The monitor is a little senstive though...changes every time I touch it...I will mount it like I am supposed to after the holidays.

I still have my airstones going fulltime...I don't dare shut them off quite yet. I am sure I am losing some CO2 by doing this....but would rather have some piece of mind. My plan is to put them on a timer when I am comfortable with my skills with the CO2. Some people don't do airstones at all....but at night...I think it will make me sleep better.

Thanks!

WC

 

[BASSNMAN]

Don't shut your system off at night. The monitor takes care of that. Your ph swings will be larger if you turn it off. Have you checked to see what your co2 content is? 10 to 25 mg/l is desired. I recently installed a similar system, just GREAT.

 

[malkore]

Yes, since White has a pH monitor, they needn't worry about setting up airstones on timers or anything like that.

 

[WhiteCloud]

I haven't checked what the CO2 is yet...waiting until I get down to 7.2 or 7.1. From the equation and my KH....I won't be in the 10-25 range until I reach that pH. I have my pH at 7.5 now...and bringing it down slowly.

How fast do most people decrease their pH when installing a new CO2 system...Can I speed up the process? I was guessing the slower the better.

Thanks

WC

 

[travis simonson]

I run the same exact CO2 system on my 125G and it works like a charm And I second the advice on leaving it on 24/7 - with the pH controller there's no need to shut it off at night, it will take care of that itself and you won't see any pH swings due to the CO2 being shut off at night. If you lower the pH to target levels over the course of a few days you should be in the clear, just be sure your KH stays stable (test frequently the first week) so that you know your CO2 levels are not getting too high. You're going to love what it does for your plants.

 

[betowess]

You may need to occasionlly add a little crushed coral or oyster shell material to your cannister filter to replenish depleted CC and KH if you ever decide to run your pH in the mid to high 6 pH which plants love. Usually a half cup of CC material will do it. Of course, all this depends upon your water's parameters. Here is a link to some pretty helpful charts figuring out CO2 concentrations based upon pH and KH. Maybe you already have checked out Chuck Gadd's site, but if not, here is a link. http://www.csd.net/~cgadd/aqua/