DIY CO2 for Dummies, with photos please

Does anyone have a step-by-step photo guide of how to make a DIY CO2 set-up for a 30-gallon tank ?

 

Check out my old ppost everyting you need is threre. if you can't find I can send u a pm

 

Here's a link to the basics with pics:

If you need more details I will be quite happy to help. I've been doing these things for many years now so I consider myself rather good with them & the best way to use them.

 

I was with you in that blog post, Nutter, right up until you went to the "applies to Juwel aquariums only" part.

With a non-Juwel tank, where / how do I get the CO2 into the water ?

 

You can just ignore that part. The actual co2 generator is the same regardless of tank brand.

There are a few different options depending on what kind of filter you are using. With the Bio-Wheel you will probably be best served by using a ceramic airstone. They are used the same as normal airstones but they are hooked to the co2 line instead of an airpump & the bubbles they produce are much finer than a normal airstone. If you want the cheap way out of it you can shove a small piece of a wooden chopstick into the end of the co2 line & put that in the bottom of the tank. Hold it down with a large pebble or some substrate. The chopstick will get clogged pretty quickly though & need replacing every couple of weeks. You could also look at bubble ladders. The bubbles enter the ladder at the bottom & slowly work their way up the ladder getting smaller along the way as the gas diffuses into the water. If you had an internal or canister filter there would be more options but I won't go into those as I believe you have the Bio-Wheel.

 

Actually, the tank I'm looking into this for (mainly, at least) has a canister filter.

 

With most canisters the easiest way to diffuse co2 is simply to hook the co2 line to the filters pickup. The co2 bubbles will be drawn through the inlet hose, through the media & then smashed apart as they travel through the impellor & finally through the outlet into the tank. Works great. Alternatively you could make a diy diffuser out of an old gravel vacuum or small soda bottle or you can make an inline diffuser which is the most effective of all. If you like the idea of the diy diffusers I can give you details on how to make them.

There are commercially available units such as co2 bells but I don't find them to be worth the money when it is so easy to just hook the co2 line into the filter pickup.

 

Can you explain two of them for me, please - the "inline diffuser" concept, and the "filter pickup".

Thank you.

 

To do the pickup is the simplest. All you do is run the co2 line to the intake of the canister filter. Place the co2 line directly under the intake so that the co2 bubbles get sucked into the intake & through the filter. If the pickup has one of those little plastic cages on it you can cut one of the little plastic bars so that you can jam the co2 line directly into the intake.

An inline diffuser is simply a canister made out of PVC that hooks into the filters hoses either before or after the filter. Here's a couple of links to the basic design principle: The diffuser should be made of larger diameter PVC than this persons design & should contain bio-balls or some form of media to help break the bubbles up.

Here's a thread that has my basic design in it:
This should be made out of 4" diameter PVC. I had my diffuser hooked into the inlet hose directly before my canister filter. Water flows infrom the top & exits at the bottom. Cut the inlet/outlet hose to fit to the diffuser unit. Sorry I can't give you pics of it, I have since given the unit to a friend. I am planning on building another one in the next couple of months & will create a thread on it that you can keep an eye out for.

 

Thank you again.

I'm pretty sure I read something about putting the CO2 into the intake of the canister isn't good for the filter - it degrades it or something.

 

I've been doing it for years & never had any problems. It supposedly wears the impellor out quicker but I don't think it has any effect unless your pumping in large amounts of co2. I've had my twin 5lt generator rig running through my Eheim for about 5yrs. Still havn't had any problems & that rig is pumping large amounts of gas into the filter. I know several people that have similar sized rigs on different brands of filter & havn't had any problems.

If you don't like the idea of putting the co2 line to the pickup then perhaps the inline diffuser is the way to go. Alternatively you could do one of the ones that goes inside the tank & is made from a gravel vacuum or buy a commercial unit. I don't find the commercial units to be very good though myself & I've tried an awful lot of them.

 

How do you tell when you have enough, or too much, CO2 in a tank ?

I put together a miniature version today for the 6 gallon - a 710ml bottle (since that's what I had on hand) with 1c sugar, 1tsp yeast and a pinch of baking powder. Put a small hole in the lid, pulled the tubing through (what a PITA, btw), cut the tube, put on the check valve, and it's attached to an air stone in the tank.

Am I on the right track ? Obviously the 32g will require a larger set-up, but this was just for a try - and figuring that the Betta in the tank breathes air up top, so is less likely to suffer if I get too much CO2 in the water (at least I HOPE I'm right on that).

 

With diy co2 it isn't very easy to get an accurate measure of how much co2 is actually being dissolved into the water. Don't worry about if there is too little co2 in the tank, just if there is too much. The first thing you will notice if there is too much, is an increase in the fishes gill rate & they may be at the surface of the water or making frequent trips to the surface. If you see that you need to lessen the amount of co2 being absorbed into the water or produced by the mixture. Increasing surface movement to allow the co2 gas to diffuse back into the atmosphere is about the most effective means of reducing the amount of co2 in the water. The mixture you have made up will produce a large amount of co2 for a short period so it will pay to keep a pretty close eye on your Betta. It will be better able to deal with a shortage of oxygen than most other fish so it is a good choice to be trying this with.

The basic principle of the yeast recipe is that the more sugar there is, the longer the mixture will last. The more yeast there is the more rapidly co2 will be produced but the mixture will not last as long. The size of the generator bottle will have a large impact on how long the mixture will last for as well. I use 2 cups sugar & 1tsp bakers yeast in 5lt bottles. That mixture lasts me 4-6 weeks depending on the temperature. The same mix in a 2lt bottle will only last 2-3weeks. Forget the bicarb. Contrary to popular opinion I have found that mixes containing bicarb actually don't last as long as mixtures that are just yeast & sugar. The yeast will die from the alcohol being produced long before they die from the lowering PH. The temperature will have a large effect on how fast the mixture is producing co2 as well. The warmer the temperature the faster the reactions take place & the more gas is produced. The opposite for cold weather. To get a more consistant level of co2 production you can put the generator bottle/s in buckets of water. You can install cheap aquarium heaters in the buckets if you are in a particularly cold environment.

 

Okay - I went up and checked on this contraption.

Bubbles coming up steady - like an air pump on a low setting maybe - and the Betta hanging out in the top corner.

I'm guessing that that is not a good sign.

I unhooked it.

Found a 2L bottle, cleaned it up (no soap) and put in about 1/2 c sugar and a 1/2 tsp yeast, filled about 2/3 up with water.

Should I leave that 2L on, or just unhook the whole get-up for now ?

 

The Betta may just be hanging out at the surface anyway. It can be a bit hard to tell with them. Look for the increase in the gill rate. That is the best indicator you have.

You can leave the 2lt bottle hooked up. I would add another 1/2 cup of sugar to that mixture. What are you using to diffuse the co2 gas?

PS: Forgot to mention that the easiest way to get the airline through the lid of the generator is to cut on a 45 degree angle across the airline. Poke the end with the angled cut through the hole in the lid & then pull through with pliers. Twist it around a bit once you have pulled it through to make sure that it is sealing properly. Sorry. I should have mentioned that much earlier.

 

I'll do the extra sugar thing tomorrow. I've had about 2 hrs tonight without my husband or kids - during which time I taped and painted the main wall in the living room, and created a new CO2 bottle - but they'll all be home soon, so I'm going to sit back and enjoy the last few minutes of peace I have

I had no trouble with the tubing and the cap - I'd read the angled cutting already, and it worked quite well.

Oh - and it's just a regular airstone I'm using right now. I've read that the wooden ones are better (finer bubbles?) and I'll likely go that route in the long run, but at the moment, I'm just using what I already have on hand.

I do want to thank you, Nutter. For both your advice and your patience with me. It's much appreciated.

 

Your very welcome for the help & it hasn't required any patience. It's been a pleasure to help you.

There will only be a very small percentage of the co2 coming out of the airstone being dissolved into the water so you shouldn't suffer from any overdosing effects. I think your Betta just felt like hanging out in the corner.

 

Does the CO2 lower pH values ?

 

Yes co2 gas does. Flourish Excel should not.

During the lights off phase the plants also give off co2 gas which will lower the PH even further. I recommend that an airpump be run off a timer so that it is on when the lights are off. A small airstone is all that you need to have in the tank. The extra surface disturbance created during the lights off period will help dissipate the extra co2 gas & help keep PH levels more stable during the day/night light cycle. The airpump should not be running during the lights on period.

 

if ive read correctly, your six gallon betta tank has a biowheel on it right? Ive found the output from these to be sufficent surface agitation as far as keeping the co2 levels in check at night, When I took my biowheel of my tank, my fish were gasping for air at the top the next morning. But, id listen to nutter as hes more knowledgeable than I in this realm, I just thought I would input that, it works! Unless you have the eclipse system, I'm not sure how those work exactly, if the biowheel output is splashing the surface, id assume it would be fine.

 

The 6 gallon is an Eclipse, and yes, it has a biowheel. There is some splash - not a huge amount, but definite surface agitation.

 

How can I either break the bubbles down smaller, or keep the bubbles in contact with the water longer, using stuff I already have here (which isn't much - sponge, a couple of riser tubes from UGF, BioMax . . . ) ?

 

I'm not sure how you would be able to do it with the stuff you do have, short of just leaving the airline tubing in the tank, but I don't think that's very efficient, I think you would at the very least need an airstone, I was thinking maybe you could put the airline tubing inside the sponge but there's really no way that would break up the bubbles, The only thing I can think of is either the internal filter or a powerhead, which was mentioned before, I think, sorry I couldnt be more creative, =/

 

maybe you could stick one of the riser tubes into the sponge and stick the airline tubing from your co2 at the bottom of that, the bubble will be stuck under the sponge instead of going straight to the surface, that would increas the contact time between gas and water, give it a go!


*edit*
sorry for the horrid , I just did it right now, but, that's basically what it would look like, and it could work till you could employ a more sofisticated method.

 

The splash from the bio-wheel is constant & will have a constant effect on the PH levels from the co2. The idea of the airstone is to stabilise the swing that occurs from day to night. At the moment it won't make a huge difference as between the bio--wheel & the lack of a good diffuser, the co2 will be having very little effect. With a filter that doesn't cause much surface disturbance & an efficient diffuser the co2 can cause big PH swings. I have seen the PH swing from 7.4 during daytime down to 6.2 by the next morning.

Try wrapping some fine sponge around the airstone. You can hold it on with an elastic band or some fishing line. Alternatively you can have an iverted cup to collect the bubbles as they come out of the airstone. That will expose the co2 to the water for longer. It is basically the same as a co2 bell diffuser. They are supposed to be placed where there is maximum current but that will be a problem for you with a bio-wheel & Betta. You could also jam a 1/2" piece of a wooden chopstick in the end of the co2 line to replace the airstone. Very fine bubbles will come out of the chopstick. Because they are so fine they take much longer to reach the surface.

 

You guys are great !

Okay - I totally forgot to hook up my air pump last night. It's not even plugged in right now, actually.

This morning - my pH was at 6.4 or 6.6. It's usually around 7.4 to 7.6 !

I'll unhook the CO2 tonight I think - until I can get hold of another timer power bar, since my timer only has 1 outlet spot, and the $15 timer bar has 4.

On another note - I kind of put together the ideas above, and managed to significantly break down the size of my CO2 bubbles. Not microscopic, but seriously small now. I took my small airstone (it's about 1", maybe 1.5"), wrapped it in a piece of "polishing pad", and stuffed that into a small section of the riser tube (about 2"). Pushed that down into the gravel, and no more big bubbles.

ETA : My biowheel barely moves, and the 'drop' from it to the water surface is at most 1/2". No splash, though there is surface movement. I could probably bring the water level up to all but touching the output from the filter, but then it would overflow as I played with the airstone and CO2 stuff.

 

Imagine the PH drop if the co2 was more efficiently diffused & there was no surface disturbance at all!! It can be quite significant. I wouldn't worry about filling the tank the extra bit. It won't make much of a difference to the level of surface disturbance by the sound of it & it would be a pain in the behind to have to take water out of the tank every time you want to do maintainance. When you disconnect the co2 either pull the airstone right out of the tank, (sounds like hard work in this case) or disconnect the line from the co2 generator & raise it above water level quickly. If you leave it below water level it will act as a siphon & you will have water everywhere.

 

I figured I'd just do the disconnect - I've got a check valve on the line between the smaller bottle (just water in that one) and the air stone.