Of solenoids, CO2 stones, venturi powerheads, and thangs

Tom Wood

Guru Class Expert
Jan 24, 2005
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Kerrville/Austin, Texas
I bought a few of the Sweetwater diffusor stones and placed one in the bottom half of my in-tank sump. The sump is 6" wide at one end of the tank, 24" deep, and 18" front to back. (90 gallon tank) Halfway down in the sump, there is a grid of eggcrate that supports a sheet of blue/white filter fabric. The CO2 bubbles come out of the stone and gather under the fabric, then eventually burp out along one edge. The intake for my external pump is at the bottom of the sump, so the CO2 bubbles run against the water flow. Works well enough that I can make my fish go all wonky with a small twist of the needle valve.

I've also purchased one of the Rio RVT powerheads with the venturi after the impeller. I'm going to swap it out with the Sweetwater stone. My thought was that it would swirl the bubbles in the sump a little better and maybe improve efficiency. I'll see if I can set the needle valve lower once I install the powerhead. If not, then the Sweetwater stone is more economically efficient.

I've added a LOT of circulation to this tank, so letting the CO2 run 24/7 is just wasting too much. So I also bought a solenoid switch from aquarium plants dot com and I'm a little disappointed with it. Although their top gun system shows a switch that can be hard piped with copper fittings because the connections are in the sides of the switch, the separate switch that they sell has the ports 90 degrees rotated so you can't connect it with hard fittings because they would conflict with the body of the switch. So you have to use flexible tubing, which they acknowledge by shipping it with tubing fittings. Which in turn adds four new places for a leak, which it did at first.

Just thought I'd share.... :D

TW
 

Cornhusker

Guru Class Expert
Jan 23, 2005
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Re: Of solenoids, CO2 stones, venturi powerheads, and thangs

TW,take a look at AQUA BUYS.COM for inline,inexpensive solenoid,$29.99.
maybe the mist idea is catching on. regards,cornhusker :) :)
 

Tom Wood

Guru Class Expert
Jan 24, 2005
139
0
16
Kerrville/Austin, Texas
Re: Of solenoids, CO2 stones, venturi powerheads, and thangs

It seems to be working right. I keep a cup of soapy water nearby and have tested for leaks about every other day, so far so good. One of the barb fittings needed tightening, but other than that it's good.

The lower body with the ports is held on with four small thru-bolts. It seems that the lower body could be rotated 90 degrees so it could be hard piped, but I'm afraid to disassemble it and have a million little parts fall out. :p

TW
 

Cornhusker

Guru Class Expert
Jan 23, 2005
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Re: Of solenoids, CO2 stones, venturi powerheads, and thangs

Magicmagni, i've not received shipment of the solenoid yet. i think they are a little slow. i'll let you know. regards,cornhusker :) :)
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
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Re: Of solenoids, CO2 stones, venturi powerheads, and thangs

I've had 3 solenoids fart out on me and one recently was just leaking like no tomorrow.

I make sure to get the beefy ones and get a good bite on the seals before hand.

Also, place the reg/valve etc somewhere were you will not knock into it at all.

Tom, I think you'll find the CO2 monkeying and experimenting will make things rev up for your tank quite well.

If set up right, it does not take much to really get a large difference.
You can feed the output directly into the return pump for a bit more efficiency.

I do NOT suggest mist 24/7.

Turn it off at night.
You can use a power head to do this if it's the source of flow/input to the tank etc, or, you can use a solenoid.

Regards,
Tom Barr
 

Tom Wood

Guru Class Expert
Jan 24, 2005
139
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16
Kerrville/Austin, Texas
Re: Of solenoids, CO2 stones, venturi powerheads, and thangs

Well, blah.

A five pound CO2 cylinder empty in two weeks, that's not good. I didn't locate the leak, but I suspect it involves all those connections around the solenoid. When it's off the pressure builds behind it, and it seemed to me that the Sweetwater stones did better with 30-40 psi. I don't remember leak testing after it had been off a while, but if it's this twitchy then forget it anyway.

So, that's gone and I installed the Rio powerhead. Nice bubbles. I have it on the timer with the lights, so the CO2 will still flow at night, it just won't get distributed very well. Wastes some, but not nearly as much as the leakage.

TW
 

Tom Barr

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Staff member
Administrator
Jan 23, 2005
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Re: Of solenoids, CO2 stones, venturi powerheads, and thangs

Yes, solenoids are often the main culprit of hard to find leaks.
I just went through this not long ago(you'd figure having it happen once was enough to light the dim bulb inside my head but naw.... :rolleyes: )

Yes, the powerheads are good alternatives to solenoids if they break/leak etc.

I also wondered about the stability of the flow rate of CO2 gas if you simply set it open with the needle valve and never shut it off vs the open/close routine of the solenoid under 10-30psi of pressure knocking against the needle valve everyday.

I think it tends to jar the valve closed a little each time.
I leave the valve open 24/7, then the valve is much more steady. But with a good high quality valve, it did not make much difference, the clippard's it did.

Regards,
Tom Barr