Need help choosing CO2 system (what does the solenoid do?) - Aquarium Advice

bs6749 · 09-20-2007, 08:48 AM

Hey guys, I will be purchasing (hopefully) a CO2 setup for my new 125 gallon tank and I need help choosing a CO2 system. I want to use a paintball canister to run the CO2 out of it so I decided to go with a setup from RedSea but I'm not sure which one to go with to be honest. I have no experience with CO2 systems or contained air for that matter and I don't know what the solenoid does and if I actually "need" one or "SHOULD" have one. I would like your expert opinions on the matter. Here are the two systems that I am debating between:

Without solenoid: http://www.bigalsonline.com/BigAlsUS...ystempaintball

With solenoid: http://www.bigalsonline.com/BigAlsUS...eluxewsolenoid

I found the one w/o the solenoid for ~$110 and the one WITH the solenoid for ~$150 so hopefully BigAls will live up to its price matching guarantee and deliver a good deal for me.

If anyone has any setup in mind that is better/cheaper feel free to send a link to it as it would help me out greatly. Have a nice day all!

EDIT: I keep forgetting CO2 is in liquid form in the canister and not gas form. Seems like a solenoid controls the flow of fluids???

**neilanh** · 09-20-2007, 09:16 AM

I think you're going to want to go with a bigger system for that size tank. You'll empty a paintball canister very, very quickly.

The Solenoid allows you to hook the system up on a timer. With no power going to the solenoid, no CO2 will flow. once power is applied, the flow starts and is controlled via the bubble counters.

I've got the Milwaukee system. Includes the regulator, solenoid, and a bubble counter, I paid $78 on ebay for it. You can get a tank locally (welding shop, roberts oxygen) for around $80-100. Get the largest tank you can afford and that will fit, as that will minimize the amount of times you have to have it refilled per year.

I'd venture that with a paintball canister, you'll be refilling every week or 2.

theotheragentm · 09-20-2007, 11:29 AM

Solenoid valves are normally on/off valve, no in between positions for control. When you send a voltage to them, they open or close depending on whether they are normally open or normally closed. The ones used on CO2 systems should be normally closed, so while the timer is on, you are sending a voltage to it and when the timer goes off, you stop that signal.

bs6749 · 09-20-2007, 11:42 AM

So the kits would have everything that I needed minus the CO2 tank? I think I may go ahead and order the paintball setup even though I may have to refill frequently. I will just get 2-3 20oz. tanks which should last me a month or so.

What is the benefit of having it on a timer? This will really tell me if I need a solenoid or not. I can control the outlet of CO2 with the regulator right? How many bubbles per minute do you all use in your tanks? Does it depend on tank size and amount of plants? The system says it will work for tanks up to 130 gallons so I'd like to think I would be safe having a 125 and hopefully they didn't over-rate it. : (

**neilanh** · 09-20-2007, 01:53 PM

I still urge you to get a larger system. A 125 gallon tank is going to require a lot of CO2 to maintain target levels up around 30ppm. I really think you'll be swapping CO2 tanks weekly if you use the 20oz tanks. I would think a 10# CO2 tank would probably last you 6 months between fills. Besides, the hardware for a full setup is cheaper than that paintball kit you listed. Add the cost of a tank and you're only a little bit higher than the system above w/ a solenoid. I spent a total of $170 on my system with a 5# CO2 tank.

Plants, when not in their photoperiod (no light) do not consume CO2, so having it running with your lights off is essentially wasting the CO2. Regulators / needle valves can be touchy, so in order to maintain consistency you'll want to set it and leave the flow rate (bubbles per second) the same day in and day out. Constant fluctuations can lead to increased algae blooms.

rkilling1 · 09-20-2007, 05:02 PM

I have to agree with neilanh. I would not purchase that paintball setup. As mentioned, you will be running out of CO2 quite frequently.

bs6749 · 09-20-2007, 05:32 PM

How many bubbles per minute do you guys/gals run then? Should I go with the "normal" setup instead of the paintball one or should I just go with the Milwaukee idea?

If I went with the Milwaukee regulator, what else would I need besides a 10lb tank (think this is a good size to fit in my stand)? I would need CO2 tubing but what else? I don't think I will need/want to run a timer on the setup because the CO2 will also be useful for controlling the pH and if I went with discus as I MAY do it will be helpful in maintaining the more acidic water needed. How much (rough estimate) would it be to fill a 10 lb. tank and how often would I need to refill it assuming that I am running at the same bubble rate that you all are running (continuously vs. a timer if you have one). Also, how/what is the best way to disperse the CO2? Can I hook the CO2 airline up to 1 or 2 powerheads? If I went with 2 powerheads would I need some sort of regulator between the two? Thanks for helping me out, I'd be lost without your help.

**neilanh** · 09-20-2007, 05:36 PM

I can't estimate your exact BPS you'll need. I run about 2bps on my 29gallon tank, 1.5bps on my 20 and <1 on my 2.5.

For diffusing the CO2, what kind of filtration are you going to have on the 125? If you'll have a canister filter, you can do an inline CO2 reactor. Completely hidden under your stand and you get 100% diffusion. The injection into a powerhead would also work.

bs6749 · 09-20-2007, 07:29 PM

I am ordering an XP3 tomorrow. Could you recommend an inline CO2 reactor for me? Does it work similarly to an inline heater where I'd want it hooked up to the outlet hose? Thanks again fr your help/input.

What is the reasoning for running different rates (bubbles/sec)? Is it mainly the type of plants or the size of the tank? What level should be sufficient for mainly amazon swords?

**neilanh** · 09-20-2007, 08:30 PM

Check the DIY section. A little PVC and some bio-balls (which you'll want for the XP3 anyway) makes a very workable inline diffuser. Yes, they hook up just like the inline heaters, except most run the diffuser on the intake side of the filter. I think people have said they make them at about a $15-20 cost. I've seen them sold on F&S for $80.

Size of tank, surface agitation (off-gassing), diffusion method; all these things contribute to how many bps you'll end up running your setup at.