CO2 O2 exchange with a Sponge filter

sk8rvendz

Im thinking about running an O2 line and a CO2 line into a powerhead attached to a Hydro sponge filter. The O2 pump will be on a timer to run during my night cycle to remove excess CO2 and oxygenate the water. Ill run each line in with its own backflow and T them to one line into the head. the CO2 is DIY and will run 24-7. This is for my 60 gallon planted. Questions, comments, suggestions?

DanMarion

Seems to me like it would work for your CO2. I don't think its necessary for O2 though. The bubbles off of your airstone aren't what add O2 to the water, its the surface disruption. You want your bubbles to break the surface to exchange O2.

sk8rvendz

the CO2 and O2 will run into a powerhead attached to the sponge. does that make more sense?

sk8rvendz

Speaking of CO2, what recipe do you prefer? I have used granulated sugar but that seems to give a burst of CO2 then a slow trickle. I have read about the Jello method but have not tried it. Currently, Im usiing Jolly Ranchers in my bottle. the hard candy dissolves slowly and I get a constant CO2 flow for 7-8 hours then it trickles off.... This is on my 60 which is in my classroom and my students delight in giving the plants their "Candy."

DanMarion

I use sugar/yeast. I've found that by playing with the amount of sugar you put in will affect how long you get good pressure.

And I understand that the O2 will be running to a powerhead, but I still don't think it will do much. Air bubbles don't transfer much O2 to the water, that is all done at the surface. Increasing surface movement is the best way I know of to increase O2 levels in the water.

Mikaila31

its DIY. Completely forget the O2 line at all. Minimize surface movement most you can. In a 60 gallon you are really pushing DIY you should not even be worrying about excess CO2 at night with DIY. I doubt your tank will be able to even reach ideal CO2 levels in the first place, so trying to lower them at night is going to make the co2 kinda pointless IMO.

sk8rvendz

Before I added the Sponge with a bubbler, my fish were gasping at the surface. My CO2 runs directly into the intake of a Fluval 305. My plants are stronger since I added the yeast/jolly rancher. KH and PH are constant so I am unable to see a change in CO2. Since I added the bubbler, my fish are happier, my plants are still happy, and the algae is almost gone.

What im hoping to do is have both worlds. if the powerhead runs the sponge 24-7, CO2 runs as long as the rancher holds out, and air is added only at night to break the surface and oxygenate the water, everyone wins. or am I still over working it?

redchigh

I think what mikaila is saying is that DIY CO2 has an extremely low output- It'll be hard to get enough CO2 into the tank to make a difference, and the O2 bubbler will decrease it even more.

If you want to use DIY co2, you might have to run several bottles.. Then it could work.



That being said, I don't use CO2 at all.

sk8rvendz

Thanks for all the advise. As my livestock population reaches max I can see where CO2 would no longer be necessary, but until then, how much is needed?

If DIY is running at 32 bubbles per minute or 1 bubble every two seconds or so, how fast should it run for a 60 to be properly carbonated. Would a pressureized tank system inject more CO2?

redchigh

A lot of that would depend on how good of a diffuser you have....

Without a diffuser at all, even 32 bubbles will be negligable.

With a diffuser, I'd start at 7 bubbles per minute, and maybe work up to 12-18 eventually (and raise it regularly by 2 bubbles a day or so. If you have an algae outbreak or if the fish gasp at the surface by the end of the day, lower it down and keep it there.) Another way to see if you have enough CO2, is to monitor the Ph drop. (Don't let it drop by more than .3 or so. Test the ph at the same time every day since ph fluctuates on its own.)

The problem with DIY CO2 is that it will vary. Having several bottles will help keep it stable.. Perhaps 3 bottles...
Start 1 on today, label it A.
In 2 days, start a second, and label it B.
In 2 more days, make another, bottle C.
2 days later, pour bottle A out and restart it.

You could use more bottles of course, but that should stabilise it.

Running the CO2 into a powerhead may or may not diffuse it properly... No way to tell.


Why you worrying about CO2?