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Cheap/Simple CO2 System? Multiple Tanks?

5335 Views 19 Replies 10 Participants Last post by  petn
I have two tanks that are about a foot apart. Both are meant to be heavily planted, both are meant to have lots of ground cover. I'd like to boost growth with a CO2 system. One tank is 34 gallons and the other is 29 gallons.

1. What's the cheapest CO2 system for these size tanks?
2. Is there a system that could produce CO2 for both tanks?
3. How expensive is it to get new CO2 cartridges and stuff? Monthly running cost?

Also, in the 34 gallon, there is a large skimmer because it was meant for saltwater. It produces craploads of tiny tiny bubbles. Will this supply CO2 and oxygen to the tank, and would it be beneficial to run 24/7? I also have a skimmer I could add to the 29 gallon, if it would do the same thing.
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Cheapest system is a DIY set up using yeast and sugar. You can use multiple 2L bottles for each tank and rotate 1-2 out each week to maintain co2 levels. It's easy, but weekly solution changes get old pretty quick and you can never perfectly dial in your co2 levels.

You can get a pressurized system that will run both tanks, all you need is a decent quality regulator and a manifold or T fitting so you can run more than one needle valve. You will need a bigger co2 tank obviously unless you want to refill more often.

I use a 5lb tank on my 20 long and it costs around $20 to get it swapped out for a full one. The disposable co2 cartriges that you see running the smaller systems are usually MUCH more expensive, and IMO are not worth buying at all unless you're running a very small tank. If you're serious about co2 I'd say get the largest tank you can afford/have space for and go with that, and get a decent quality dual stage regulator to go with it. It should last you for many years.

As far as the skimmer goes, it should add oxygen to the water but won't add much in the way of co2. A general rule of thumb is the more surface agitation you have, the more co2 in the water will be lost to the atmosphere. A lot of people run an airstone at night, but so far in my application I haven't had a need for it.
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The dude at the LFS today said it'd be at least $200 which sounds kinda high...

I just want the cheapest thing possible or nothing at all. I don't want to spend 10 times more than it took to set the tank up for something that will poison my fish lol.

The guy said without CO2, the dwarf baby tears would float to the surface constantly when I filled the tank with water after a dry start... Is that true?
Best cheapest way is DIY. Read Oldpunk's how to build a CO2 regulator thread. Getting into CO2 is expensive (excluding yeast bottles). $200 is a good price already.
Can I successfully grow HC with only high lighting and fertilizer?
I don't think so. Your HC would be covered in BBa or other algae in days without high co2.
Will this work? I know how to make this easily and should have most of if not all of the parts...



I'd use a diffuser instead of an airstone, like this... http://www.ebay.com/itm/New-Fish-Na...173?pt=LH_DefaultDomain_0&hash=item3cda9dc7e5
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I was thinking one 10lb tank with a dual manifold regulator and you would be set for both, but that is definitely not the cheapest route. Personally, I think DIY is pushing it for tanks of your size. Add in that you want/have high light and DIY is just not consistent enough in its output, IMO.
Folks say diy is cheapest. I'd like to see a cost analysis done on everything required weekly including time spent maintaining. I feel like its one of those things that'll just keep being an expense
I have 120 in my system and works great. DIY works great but harder to,control. Its a better investment to do it right and not waste time. CO2 won't poison your fish, If your levels get to high it will deplete the water of oxygen. Don't buy the garbage that fish stores sell either. I seen them sell systems for 3x what they are worth. My 20lb co2 tank Got it on sale for 40$ and its lasted a year and still going.

-Chris
Wait, so is all I need a CO2 tank and a diffuser? This is so confusing...
You can make your own regulator/controller without solenoid for 30.00. You would have to turn it on and off manually. You can also purchase a decent premade regulator for less than 40. Also no solenoid.

I have one I made, and one I purchased. Both without solenoid. Both work well. I also have a regulator with solenoid that I don't have to touch except to refill co2 tank. They all work well and are fairly cheap.

Sent from my Nexus 5
You can also purchase a decent premade regulator for less than 40. Also no solenoid.
Where are you finding those? Most regulators I am seeing are at a much higher price point,even the poorly made bundled ones.
You can make your own regulator without solenoid for 30.00. You would have to turn it on and off manually.
or leave it on 24/7. I did this with my second regulator b/c I had no solenoid. just keep an eye on things the first few nights and make sure you've got ample surface rippling to promote o2 exchange.
So hopefully to make it simpler:

1. Don't look for the cheapest. Identify what you need and then determine what is best of you and your setup with somewhat of a budget in mind. A "system" usually consist of a tank, regulator, diffuser/reactor, solenoid, bubble counter. You can do without a solenoid, which turns on/off atuomatically but I would recommend.

2. You can buy one CO2 tank and get a regulator with a dual output to provide CO2 to both tanks. Would need reactor/diffuser, and bubble counter per fish tank.

3. Price to refill a CO2 tank varies. A 10lb tank will cost around $20 and with your size fish tanks would probably last 4-5 months.

Get rid of the skimmer.
or leave it on 24/7. I did this with my second regulator b/c I had no solenoid. just keep an eye on things the first few nights and make sure you've got ample surface rippling to promote o2 exchange.
If I have minimal surface ripples with no CO2 system, will the CO2 be higher than usual and bearable for the fish? From what I'm reading, it seems like you can only do it the $4,000 way or the not at all way. :icon_roll
Guppy, the picture you added is a not-very-good way to do that.
Here is the better way:
1 = 2 liter soda bottle. Filled to about the shoulder with water, 2 cups sugar and 1/4 tsp yeast. I add a pinch of KH2PO4 just in case the yeast needs these minerals (my tap water is pretty soft). 1 hole in top is slightly smaller than the tubing.
Cut the tubing at an angle and stuff it in, get it started. Grab the pointed cut with needle nose pliers to pull it through. Do not take it very far into the bottle. About an inch is fine.
2 = separator bottle. I use the (12 oz?) Gatorade or similar bottle. Large lid has 2 holes, similar to above.
the tubing from the yeast generator goes in pretty far. In fact, I cut a piece of rigid tubing such as came with certain under gravel filters. The other tubing is only into the bottle about an inch, and goes to the tank.

I have had the separator bottle almost fill with fluid, yet the aquarium is safe because there is that much buffer that you can catch it before something gets into the tank.

I have also seen even safer versions where the holes through the bottle caps have some parts from model airplanes to pass through the caps. But mine have never come out. The secret is to drill the hole small enough that it compresses the tubing enough to secure it, but not shut off the flow.
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When I had 2 x 29 gallon tanks near each other I set up 3 bottles and cross-connected each bottle to each tank. Then I swapped out 1 bottle per week to keep the flow as even as possible.

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Where are you finding those? Most regulators I am seeing are at a much higher price point,even the poorly made bundled ones.
ThatPetPlace sells a controller/regulator for paintball tanks for 30.00 something. When I purchased this it was 29.99. and has worked well for over 6 month and is simple in design so no parts to break. You turn the knob for your desired bubbles per second. Needle valve takes some time to get use to, but that was the case for all my co2 systems.

I would link directly but that seems frowned upon here.

EDIT:

35.21 : Regulator
16.95 : Co2 20oz tank
??.?? :Co2 tubing + bubble counter/check valve + diffuser/reactor

total price depends on parts you already have. I already had everything when I purchased the regulator since this was my second regulator.
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Guppy, the picture you added is a not-very-good way to do that.
Here is the better way:
1 = 2 liter soda bottle. Filled to about the shoulder with water, 2 cups sugar and 1/4 tsp yeast. I add a pinch of KH2PO4 just in case the yeast needs these minerals (my tap water is pretty soft). 1 hole in top is slightly smaller than the tubing.
Cut the tubing at an angle and stuff it in, get it started. Grab the pointed cut with needle nose pliers to pull it through. Do not take it very far into the bottle. About an inch is fine.
2 = separator bottle. I use the (12 oz?) Gatorade or similar bottle. Large lid has 2 holes, similar to above.
the tubing from the yeast generator goes in pretty far. In fact, I cut a piece of rigid tubing such as came with certain under gravel filters. The other tubing is only into the bottle about an inch, and goes to the tank.

I have had the separator bottle almost fill with fluid, yet the aquarium is safe because there is that much buffer that you can catch it before something gets into the tank.

I have also seen even safer versions where the holes through the bottle caps have some parts from model airplanes to pass through the caps. But mine have never come out. The secret is to drill the hole small enough that it compresses the tubing enough to secure it, but not shut off the flow.
------------------------------------------

When I had 2 x 29 gallon tanks near each other I set up 3 bottles and cross-connected each bottle to each tank. Then I swapped out 1 bottle per week to keep the flow as even as possible.
Thanks, that helps out a lot!

Pardon my ignorance, but what does the separator bottle do? I've seen it in other DIY setups but don't see how it does anything...
2kg Fire extinguisher for £24 on eBay. Then go for www.co2art.co.uk and get the rest. Get itself a splitter for your 2aquariums too. I'm having 4, refilling 2kg cylinder monthly for£15. U can get it all for about £150 INCLUDING Solenoid. After experimenting with yeast, I can tell u , it's worth it.good luck

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