Reverse flow?

chlskt · 05-05-2005, 02:05 AM

I finally got water in the reef tank!!! One problem, how do I keep the water from back flowing into the sump when I turn off the pump? I tested it to see if the electricity went out if the sump would overflow. It doesn't! The only problem is, is the water siphons back into to sump. How do I fix that?

Jeni

aussiereefer82 · 05-05-2005, 02:12 AM

Put 2 small holes in the pipe about 1" below the water level, when the water gets below the holes, air will get in and break the siphon. Use 2 holes incase 1 gets blocked.

wolfie · 05-05-2005, 02:24 AM

Quote:

Originally Posted by aussiereefer82

Put 2 small holes in the pipe about 1" below the water level, when the water gets below the holes, air will get in and break the siphon. Use 2 holes incase 1 gets blocked.

so you mean the pip that is from the return pump into the main tank?

aussiereefer82 · 05-05-2005, 02:27 AM

Yes in the return pipe.

I was guessing that is what Jeni was talking about.

skeety · 05-05-2005, 11:19 AM

some backflow is normal though, right?

Even with the holes, there will still be some drainage down into the sump, just because of the nature of the overflow.

correct me if I'm wrong.

motorslave · 05-05-2005, 11:37 AM

That depends on where the holes are.
If your sump will handle tha amount of water that siphons down I would worry about it. Thats the hole idea in having extra room in the sump. As long as it doesnt overflow youre good. If you realy want to tinker some more you could put a one way check vave in line where the water returns down to the sump. But, these are know to lock up after a while from what Ive heard.
HTH

Robert

chlskt · 05-05-2005, 01:04 PM

I'll give those holes a shot. I encountered one more problem, the return pump is too strong, I'm getting bubbles in the main tank. So I have to go buy a slower pump.

Now, putting holes in the return pipe, won't reduce the output by too much right?

DataDude · 05-05-2005, 01:13 PM

I put two small holes in the return pipe on my 75g. Depending on the size of holes you drill, you shouldn't realize any significant flow reduction. I drilled two 1/8" holes. It Works like a charm. Don't forget that should you have a power outtage or shut off your pump, your overflow will continue to drain into your sump until the water level drops. You'll want to make certain you allow enough room in the sump for that also.

Tim224DT · 05-05-2005, 02:45 PM

When my pump shuts off i get only about 2-3 gallons of water back flow. I did the 2 1/8" holes on the return line.

Tim

wolfie · 05-05-2005, 08:44 PM

Quote:

Originally Posted by DataDude

I put two small holes in the return pipe on my 75g. Depending on the size of holes you drill, you shouldn't realize any significant flow reduction. I drilled two 1/8" holes. It Works like a charm. Don't forget that should you have a power outtage or shut off your pump, your overflow will continue to drain into your sump until the water level drops. You'll want to make certain you allow enough room in the sump for that also.

hmm that bring up another question. How do you stop the overflow from getting more watter into your sump?

Is there a way to do that or one just have to wait till it drain all the watter out of the main tank till it stop getting watter?

Tim224DT · 05-05-2005, 09:07 PM

Quote:

Originally Posted by wolfie

hmm that bring up another question. How do you stop the overflow from getting more watter into your sump?

Is there a way to do that or one just have to wait till it drain all the watter out of the main tank till it stop getting watter?

You drill two holes 1/8 in on the side of the return line about 1/2 in below surface of the water or less if you can without it spraying out of the water. When the pump is shut off the return like creates a siphon. When the water level drops to the holes on the side of the return it will break the siphon. So the closer the wholes are to the surface of the water the less water will go into your sump when the pump is off.

Tim

wolfie · 05-05-2005, 09:19 PM

but is that just to stop the watter from the return pump from getting bact into the sump? And what about the watter from the over flow?

Tim224DT · 05-05-2005, 09:24 PM

Quote:

Originally Posted by wolfie

but is that just to stop the watter from the return pump from getting bact into the sump? And what about the watter from the over flow?

The overflow only lets water into the sump that has been pumped from the sump. When the pump is turned off the water in the overflow stops flowing because the pump is no longer adding water to your main tank to overflow into the overflow(did that make sense?) So when the pump shuts the wholes in the return like will break the siphon asap and stop the water from getting back flowed.

Tim

drsyme · 05-06-2005, 07:09 AM

Quote:

Originally Posted by DataDude

Don't forget that should you have a power outtage or shut off your pump, your overflow will continue to drain into your sump until the water level drops. You'll want to make certain you allow enough room in the sump for that also.

Generally the overflow flow is higher than the flow from the return, so that the water in the tank IS ALWAYS at the level of the overflow. When the power shuts off, and the pump stops, the water draining in the overflow stops essentially immediately.

The problem is what was brought up originally and that is how to stop the back siphon when the pump stops. And the holes work, but you have to have enough room in the sump to accomodate the amount of water that backsiphons before the level drops down to the level of the holes.

Does anyone ever have the return actually above the water level? This would be noisy I understand. But it would help with air exchange and there would be no potential back siphon. (I might set mine up like this before I go on vacation.)

Twitterbait · 05-06-2005, 06:25 PM

Quote:

Originally Posted by chlskt

I'll give those holes a shot. I encountered one more problem, the return pump is too strong, I'm getting bubbles in the main tank. So I have to go buy a slower pump.

Now, putting holes in the return pipe, won't reduce the output by too much right?

In regards to your pump being too strong... Don't spend the money on a smaller pump, just get a nice PVC ball valve in the return line then you can adjust the flow of water into your tank. the two holes in the return is the right idea to stop the siphon plus if you have to turn off your tank you can always use the ball valve to stop the siphon.

Reverse flow?

Ball Valve