Stand pipe is sucking air

Lighting, filtration etc
ingg
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Stand pipe is sucking air

Post by ingg »

Pump just too powerful?

When I crank the pump, it starts to suck air from the top vent of the stand pipe, slowly filling the co2 reactor with air.

I have to really crank it down to get it to stop doing it, shoulda bought a smaller pump maybe? Out of ideas, it is driving me nuts here.
Dave
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Ghazanfar Ghori
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Post by Ghazanfar Ghori »

Crank it down - otherwise you risk cavitation and may damage your pump!
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FrannyB
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Post by FrannyB »

Had to look that term up!

Cavitation is a general term used to describe the behavior of voids or bubbles in a liquid. Cavitation is usually divided into two classes of behavior: inertial (or transient) cavitation and non-inertial cavitation. Inertial cavitation is the process where a void or bubble in a liquid rapidly collapses, producing a shock wave. Such cavitation often occurs in pumps, propellers, impellers, and in the vascular tissues of plants.
Francine
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http://www.capitalcichlids.org
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Ghazanfar Ghori
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Post by Ghazanfar Ghori »

BTW - cavitation in your MAG9.5 may sound like sand or a small peice of gravel
got in there or something. Looks like your standpipe is not delivering water fast
enough. You may need to rethink the plumbing a little bit if you want to
crank that pump up.
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maddog10
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Post by maddog10 »

If I remember right, the top of the standpipe was u-shaped and had a strainer on it. Try to block off the top 1/4" or so of the strainer (highest part). Just trying to make it pull water from lower down on the strainer and keep air from being drawn in.

What about lowering the standpipe.

Do not know if any of these will work, just trying to put ideas out there.

I do think you are going to trap air in your CO2 reactor (like I said at the meeting) unless you are flowing water through it super fast. You need to figure out where the air is getting trapped and add a relief valve. You will just have to bleed it off when it traps enough. Thinking on this last night, it would be harder for air to get trapped if the entire reactor is above the pump that is feeding it (but this will probably make the reactor very inefficient). Just more ideas. As everyone knows I am new to all of this, so they may be really stupid ideas, but every now and then I hit on a good one (just by dumb luck) :wink:

If I didn't have people coming over today, I would be right out there with you trying to figure it out (seriously).
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maddog10
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Post by maddog10 »

Any updates? Everything up and running ok?
ingg
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Post by ingg »

Never got it resolved.

I shut the loop down until I can work on it later this week, too much going on to deal with it right now.
Dave
ingg
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Post by ingg »

Well, thanks to a stop at Scales, might have a solution to this.

Wish I remembered the guy's name, I in my head call him "the salt guy" - I think he runs the out services end of things?

Anyhow, got to talking to him today and asked how to fix the bubbles and waterfall effects, and he had a brilliant and stunningly simple solution.

I have to revamp my plumbing for it, but check this out.

After the pump, split the return line. Take one end of that line right back into the overflow, and have a valve on it - use this to refill the overflow.

This essentially lets the pump run full out at X gallons, but the overflow thinks it only has to pull X - (return split) gallons, so the overflow waterfall stops. CO2 reactor sees full flow through it, overflow sees less pull from main tank needed. Sweet!

Dude is smart. :) That never even hit me! Now, to build it, hehe.
Dave
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jcali10
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Post by jcali10 »

I'd like to comment but I can't. I was lost a long time ago. LOL
Joe
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Aaron
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Post by Aaron »

I'm with Joe. I'm a diagram sort of guy. :D
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