Gurgling overflow

[stevil]

I swapped out my older return pump for a Mag 12 to encourage more flow (and because I got a good deal!)

 

My setup is pretty simple, 90 gallon All-Glass equipped with a single corner overflow, 1 1/4" drain into a 20 gallon sump w/ a protein skimmer and then a single 3/4" return now powered by the mag 12 pump.

 

I'm not sure how to describe this, but with the new pump the tank now has a rhythmic flow to the drain. The overflow area will fill up and then qickly drain into the sump, gurgling noise and bubbling in the sump, slow down, fill up and then drain again. It is also much louder than it was before.

 

Pinching the return hose eliminates this (but then I'm getting less flow, which seems to defeat the purpose) and taking the drain hose partially out of the sump water seems to help (but then it's much louder).

 

I could always put the old pump back in. Honestly I'm not sure how much flow is enough (or too much for that matter)

 

I could also put a restrictor on the new pump, assuming I'd get more flow than the old pump even if it was restricted.

 

Is there anything I can do to regulate the drain? Is this what a series of baffles would do in a sump?

 

Any other words of wisdom or ideas?

 

Thanks!

[BeltwayBandit]

Ahh the ol' toilet flush overflow...

 

You just need to get more air into the overflow. What is happening is it is creating a siphon and then breaking the siphon. Are you using the stock overflow AGA overflow kit?

 

Or did you make your own Durso standpipe?

 

Either way they are basically the same thing. you need to enlarge the hole on the top of the standpipe to allow more air into the pipe. If there is a cover on it try just taking the cover off to see if that will allow the flow to equalize. If it does, you are fine you can just enlarge the hole. If the water level rises and overflows into the hole you are pushing too much water.

 

Make sense?

 

Or, you can plumb your return via a SCWD. This will kill two birds for you. One it alternates the flow between two returns instead of a single one giving you better movement, two it restricts the flow some so that might solve your flushing problem.

 

BB

[stevil]

That does make sense.

 

What I have is the All Glass Megaflow. So I basically just need to drill out the very topmost nipple thing on the pipe stand? OR, do I enlarge the side holes? I can't see any kind of cap on the pipe, without taking off the entire thing and just leaving a straight drainpipe.

 

Is this thing the SCWD you are referring to? Then I would just add a length of PVC and some elbows with an extra nozzle? Correct?

[BeltwayBandit]

That does make sense.

 

What I have is the All Glass Megaflow.  So I basically just need to drill out the very topmost nipple thing on the pipe stand?  OR, do I enlarge the side holes?  I can't see any kind of cap on the pipe, without taking off the entire thing and just leaving a straight drainpipe.

 

Is this thing the SCWD you are referring to?  Then I would just add a length of PVC and some elbows with an extra nozzle? Correct?

46458[/snapback]

 

 

It is the top hole that you would need to enlarge. And yes that is the SCWD. You could plumb one end of it into your regular return and you would have to build a second return that hangs over the back out of PVC. It is very easy and I have built several of them. Just make sure you put a siphon break in it. Basically a small hole drilled just below the normal waterline in the tank. It will allow air to enter the pipe when the pump shuts down and prevents you from siphoning the main tank onto your floor. Trust me, it is not fun trying to clean up 30 gallons that decided to back siphon out when my siphon break clogged.

[rioreef]

I have a 90g Oceanic with the Megaflow, mag 12 return with a SCWD, just what you guys are talking about. See pictures for my setup. I do split the return for a small amount to go to a refugium which oveflows back into the sump area where the mag is. I also have true union ball valves on the drain and return for access when needed, but more importantly the valves can control the flow for either side to match.

 

Because I have the split off the Mag (valve fully opened) and the SCWD I have to limit the drain flow.

 

Plumbing coming up off Mag 12, split to right to refugium.

 

SCWD

 

Drain with true union on left. Drilled return on right with swing type check valve.

 

Right return out of SCWD to second return up the back side of the tank.

 

Second return up and over (two 1/8" holes - 90 degree from each other drilled in modular pipe for siphon break, these holes should be below water surface)

 

Chris

[DEEPBLUE]

You could try reducing your return to an 1/2.

 

Deepblue

[victorh]

I have the 90 with corner overflow also. I use a Mag 32 from the basement. I used to have the same problem, now it is totally silent. I have both lines in the overflow going to the sump. I put a valve on the 1" return to reduce the rate until water barely hits the top of the second return which is about 1" lower then the top of the overflow. I use a strainer looking piece on the 1" (they are inside the 1" foam filters) to keep it from getting clogged. The 1" is only about 12" high. My return is split into 2 that come over the top back of the tank.

 

Periodically I test it out by shutting off the return completely, once the water is high enough, it creates a siphon and sucks the water back down quickly, but I've never even come close to flooding.

 

Again.. Completely silent! I adjust the valve about once a month.

[Guest zmalexander]

Another possibility that can cause the Toilet Flushing Phenomenon...

 

If your return in the sump is actually too deep in the water, then air builds up in the drain line. As this occurs, flow is gradually reduced until the water rises high enough in the overflow creating enough pressure to "flush" the air out of the line. The water rapidly drains clearing the line of air, and then the process recurs.

 

-Zac

[HowardofNOVA]

Steve,

Like Chris say: "Second return up and over (two 1/8" holes - 90 degree from each other drilled in modular pipe for siphon break, these holes should be below water surface)"

This is very important for power outages. If you place the holes right at your desired water level, it will only take a couple of gallons drained out to break suction, allowing more water to be housed in your sump!

 

I've run SCWD since the beginning and love them for their simplicity. Good idea to take them offline about once every six month and run it and the Mag12 in a 5g bucket with vinegar and water to clean out. Make them like brand new.

Howard

[stevil]

Thanks everyone for the insight and advice. I will be keeping all this in mind as I tweak and upgrade my system. The SCWD seems like a great idea for when I get some corals and such to provide alternating current, and I like the idea of having two returns instead of one. Also, I do plan to set up a refugium at some point, so the concept behind rioreefs setup is something I think I'll emulate

 

For now, since I really have nothing in there but rock, sand and water, I swapped back the original Rio pump I had. This solved several problems - the gurgling overflow is gone, since my all-glass corner overflow standpipe can now withstand the flow (as designed, I'm sure), and my tank seems to be settling better. The current was redistributing a bunch of sand and causing peaks and valleys.

 

Also, I'm wondering if that much flow is really necessary, given the other thread on efficiency of a skimmer when flow is too much.

 

The Mag 12 is now circulating the water I'm aging in a 5 gallon bucket... a bit overkill perhaps, but at least I don't need a heater!

[JMsAquarium]

Thanks everyone for the insight and advice.  I will be keeping all this in mind as I tweak and upgrade my system.  The SCWD seems like a great idea for when I get some corals and such to provide alternating current, and I like the idea of having two returns instead of one.  Also, I do plan to set up a refugium at some point, so the concept behind rioreefs setup is something I think I'll emulate

 

For now, since I really have nothing in there but rock, sand and water, I swapped back the original Rio pump I had.  This solved several problems - the gurgling overflow is gone, since my all-glass corner overflow standpipe can now withstand the flow (as designed, I'm sure), and my tank seems to be settling better.  The current was redistributing a bunch of sand and causing peaks and valleys.

 

Also, I'm wondering if that much flow is really necessary, given the other thread on efficiency of a skimmer when flow is too much.

 

The Mag 12 is now circulating the water I'm aging in a 5 gallon bucket... a bit overkill perhaps, but at least I don't need a heater!

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If you mean as flow in the tank itself, yes, it does help in not allowing dead spots where all the poo and wastes will definitely accumulate. you can always redirect your returns now untli you are satisfied with the results. I mean, by having flow every where without having your sand look like a pile in a corner.

 

Now as far as flow through the sump, well seems that you have read the other thread. But it also means that in order to achieve high flow in the tank and slow flow in the sump, you will have to use two separate pumps, in two separae circuits. Une low flow pump for the sump and returns, either powerheads or a DIY close loop for the high flow in the tank. :P