Check valve and proper co2 level

B

binnesman

AC Members
Nov 24, 2004
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Colorado Springs
I have been switching to CO2 injection over the past several weeks, waiting for parts to come from different places. I received the regulator last week, and started injecting without a check valve and ran about 3 bubbles per sec. I am using a power head for diffusion with the outlet below the outlet from my cannister, which pushes the bubbles further out into the tank. When I finally got the check valve, I had to turn the output up to 5 bubbles per sec just to see any come into the tank. It brought my ph down to 6.4 in the morning, but settled up to 6.8 during the day (kh = 5). With 3 bubbles per sec the ph was 6.8 in the morning and 7.0 during the day. Do I have a bad check valve?

BTW, I've been wondering how I can get better diffusion of the co2. Many of the bubbles just race to the top, though many finer bubbles do make it to the whole tank.

One aside...it is so cool to see pearling, and steady streams of bubbles coming from the plants. And they seem to be healthier looking, though not explosive growth.

Thanks
 
Sounds like you are getting pretty good diffusion.
A pH of 6.7 gives you about 30ppm. That's good absorption with a power head, IMO.
To get better absorption you need to work on ways to either get more of a mist or find a way to keep the bubbles in the water longer.

Your rate of growth will also depend on light and nutrient dosages in conjunction with carbon.

Len
 
binnesman said:
I have been switching to CO2 injection over the past several weeks, waiting for parts to come from different places. I received the regulator last week, and started injecting without a check valve and ran about 3 bubbles per sec. I am using a power head for diffusion with the outlet below the outlet from my cannister, which pushes the bubbles further out into the tank. When I finally got the check valve, I had to turn the output up to 5 bubbles per sec just to see any come into the tank. It brought my ph down to 6.4 in the morning, but settled up to 6.8 during the day (kh = 5). With 3 bubbles per sec the ph was 6.8 in the morning and 7.0 during the day. Do I have a bad check valve?

BTW, I've been wondering how I can get better diffusion of the co2. Many of the bubbles just race to the top, though many finer bubbles do make it to the whole tank.

One aside...it is so cool to see pearling, and steady streams of bubbles coming from the plants. And they seem to be healthier looking, though not explosive growth.

Thanks
Click to expand...

Is your check valve brass?
You will not see "bubbles of CO2" enter your tank. Do not worry about looking for visible evidence of CO2 in your tank. Your evidence will appear by way of pH with regard to the KH of your tank water. When you see your plants pearling, and O2 outgassing in streams, you are already on your way to better growth. Also another indication is lack of algae. Are you dosing ferts? Though plants need the Carbon source, they also need macros and micros to complete the picture. If you aren't dosing ferts, you may see outgassing but your growth will still be stunted. What are your specs? lighting, heavily planted? bioload?
 
I'll give you my specs:

75g, 210w, moderately planted, flourite plus gravel substrate, rena xp3 cannister. Fish: 6 ottos, 2 rubberlip plecos, and one leftover goldfish until I get him a new home, though he seems very happy. I am doing weekly water changes of 40-50 percent and dosing KNO3 (1 tsp 2x per week), phosphorus (fleet, 2 drops per week), flourish trace (once per week) and flourish (regular, 3/4 cap, 2x per week). I was dosing flourish iron, but was getting too much algae. Since I've stopped that I get some green algae on hardscape but not enough to worry about and it is not increasing, and actually may be decreasing slightly since starting injection.

The reason I asked about the visible bubbles coming out of the powerhead was because until I got the check valve, I could see them, and now I can't unless the pressure is a little higher.

BTW, the check valve is brass. And it's even going the right way, though I did have to re-check :)
 
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ok binns....What type of reactor are you using? Aquamedic or DIY?
P.S. it is not worth the risk to ever run CO2 without a check valve...but you have it in place now, so that is good
 
I'm not using a reactor.
 
You need a reactor or a diffuser for best CO2 injection. I suggest making a reactor, they are easy to make. check out www.rexgrigg.com and check his DIY section under CO2. He has a nice, easy way to make a reactor. The way you have it set up right now is inefficient. You can contact him and he will make you one if you aren't the handy type.
You plumb it in line with your XP3 canister.
 
It seems to me there are others on the board who diffuse with powerheads. I can't run it through the canister because it stops working due to the build up of air inside..unless you're talking about the output side.
 
Yes, the reactor can go on the Output side to avoid air build up. That's the way I would do it. The whole purpose of using a in-line reactor is to diffuse 100% of the co2 in its chamber before it goes into your tank.

If you're buying a diy reactor from Rex, you shouldn't have a problem.



Lissette
 
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binnesman said:
It seems to me there are others on the board who diffuse with powerheads. I can't run it through the canister because it stops working due to the build up of air inside..unless you're talking about the output side.
Click to expand...
You can run it through the canister when you use a reactor.
If you run it the way you are presenty, much of it is wasted. It makes no sense to do it because others do it, when it isn't the way to do it. The investement is very small. Get a reactor and plumb it in the right way, or you will not be able to regulate what is injected, and the flucctuations will cause problems.
 
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