CO2 and Airstones

[rdd1952]

In reading and replying to a post eariler in the beginners section, I happened to remember something that I have thought about before but never posted to get an answer. I have read where people were injecting CO2 for their plants but were also running an airstone so the fish have enough oxygen. Are those two things in conjunction not just canceling each other out? Is the airstone not driving the CO2 that you are injecting back out of the water? Seems like it is pretty much a double waste of effort and money.

 

[jimbooo]

ok. the ammount of o2 will not effect the quantity of co2 that can be dissolved in the water.

the issue is that co2 is not very soluble and comes out of solution VERY easily. the more disturbance to the surface the more co2 will be lost.

if were talking about a bubble wall then the answer is yes you'll be cancelling out the co2 that your putting in.

however if you have a tiny air pump on a huge airstone spreading a few fine bubbles over say a foot long airstone you will not cause too much disturbance and co2 will remain in solution.

it's all about the suface agitation. personally i wouldn't bother, when your plants are flourishing they will pearl. (sorry not sure if you know but pearling is when pure o2 escapes from the plants and bubbles to the surface, ie a natural airstone.)

 

[gaya]

When i had CO2 I only ran an air stone at night because plants use O2 at night (i think) and jimboo is correct, my plants would pearl giving back O2 to the tank.

 

[rdd1952]

Thanks for the reply. I only run 1 small airstone each on my small tanks (2.5 and 5 gallon) with no CO2 and that is only to help keep the surface film broken up. I still haven't figured out why I get the film but that's another story. I don't use any airstones on the 29 gallon or 75 gallon (which has a DIY CO2 kit on it but it doesn't put out much). I just always thought it was odd that people would use airstones and CO2 together. Seemed like a waste of effort.

Edit: There have been times when I was near the 75 gallon tank that I thought I saw an air bubble go to the top but I always thought it was from the substrate or a fish. I guess that could be pearling. My plants are doing great, especially the anacharis. I am cutting about 6" off those every week. I could go into business selling anacharis. I gave my son several bunches a week ago and probably have 50 or 60 pieces in a 5 gallon bucket now that I pruned this past weekend. The wisteria and hygrophilia are also doing quite well.

 

[jimbooo]

yep agree totally.

i used one for a month at night until the plants started to pearl then connected a diy co2 bottle to the airstone instead just to keep the look. (plus 2 hagen kits)

 

[rdd1952]

I said mine was a DIY CO2 kit but it's actually one of the Hagen Natural Plant systems. I'm only running one on the 75 gallon. That tanks still isn't completely stocked but should be as soon as I can get my 4 blue rams (stocking list is in profile). Do you think I need to add another one or 2 of the Hagen kits? BTW, jimbooo, I love the tank in your sig. What plants are in it?

 

[jimbooo]

thanks mate. too much to list but it's all in my profile (click "Jimbooo")

as to the co2 do you have a test kit? JBL do a permenent test that sits in the tank all the time giving an approximate reading all the time.

just type "jbl co2 plus ph" in yahoo/google etc and you'll find it.

i have 2 hagen kits same as yours plus a 5 litre diy bottle leading to 2 foot long airstones under the gravel.

that gives me just about 25ppm co2 using 1 tsp yeast, 1/2 tsp bicarbonate of soda and 1 mug of sugar in the hagen bottles.

simmilar ratio in the 5litre but thats more for looks as the bubbles dont disolve much.

i'd say you probably need 3 hagens in total but add one at a time and take a test reading. put too much in and the PH may crash = dead fish

i think the hagen instrustions say good for 20G cant remember for sure though.

 

[rdd1952]

I don't have my Hagen instructions any more but as I remember, they had some conflicting info in them about where the bubble tube attached. I'll look into a test kit as I currently don't have one. I figured on that size tank and with the quantity of plants I had I wasn't any where near causing a crash but I definitely would want to start testing is I added more. Thanks for all your help.

 

[guppygirl]

Yeah, from what I've read, the hagens are only good for 20 gallons per system.