Intermittant Sump Problem

[tsunderl]

I have a 30g sump on my 180g tank. The inflow tubes to the sump are bigger than the return tubes to the tank and is powered by an external Iwaki pump. The sump has plastic scour pads and bioballs as well as a Magnum HOB filter for extra fitration. (For me more than any other reason.) It's been set up like this for a couple of months with no problem. Until recently.

The problem started a couple of days ago when we noticed the water level in the tank was about as high as it could be without overflowing. :eek: The water level in the sump was very low. I turned off the pump, checked for blockages, found none, moved the outflow tube a bit, and turned the pump back on. Everything is fine, for a while but that same scenario has happened 5-6 times since. This last time it happened, I opened one of the valves on the return tube so water will go back in the sump as well as be pumped in to the tank.

The pump is working fine and I've not found blockages anywhere. What is causing this??? :confuzeld:

[AndrewH]

Hmmm blockage would have been my first guess too.

Do you have a Durson (sp) or some other kind of anti-noise devise on the return? Maybe there's not enough air getting into the system?

[AndrewH]

What sizes are all the plumbing?

(total number and size)
Overflow piping diameter? Return piping diameter? What gph rating is the pump?

[tsunderl]

Pump is rated at 1140gph. Overflow diameter is 2". Return is 1". I took the cap off the standtube thinking the same, but no difference. Here's pics of how it's plumbed. There's four return jets, on at each corner. The silver thing in the middle is a wavemaker which is off at this time. Just thought of something... It could be that the baffles in the sump are blocking water flow. But I would think I'd have a backup in the sump, not the tank. Hell, I dunno!

[AndrewH]

I was kinna thinking the same thing, some how the water is getting backed up when returning to the sump, but not sure.

Hmmm...

2" return... one 2" pipe or two 1" pipes?

At 1140, you're probably sucking it dry in seconds. Being 30 gallons, I dough it's completely full so you're probably looking at say half - 15 gallons of water.

A 1140 gph pump = 19 gallons per minute, so if your sump is even a little low (10 gallons), you're looking at 30 seconds to empty it. Even at 2" of return you might not be returning it fast enough to keep water in the sump.

Simple solution: Add a ball valve (or any type of valve) on the return line to match the flow with the drain.

[kewlkatdady]

it sounds like it has been working fine in the past but now something has change...

I wouldn't say that is a design flaw, but some sort of clog.

check an double check anything that has to do with returning water to the sump.

[biggin]

As your sump builds up all the sludge and what not the down flow is not dropping as much water as your pump is pumping out.

This is the issue that Stan and I talked bout a few weeks ago.

[tsunderl]

Overflow tube is 2" going in to the sump which yes, equalizes at about half full (15g). The return tube from the sump back to the tank is 1". It splits at the top of the overflow in to two 1" tubes, each going to the 4' sides of the tank.

What's throwing me for a loop is that the backup is in the tank. If you look at the first pic, the water level is normally about halfway up the teeth on the overflow box. When it backs up, it's all the way to the acrylic across the top of the tank.

The other things are that the problem started over the weekend with no prior problems and it doesn't happen all the time. I have the equalibrium level marked on the sump and keep it at that level. If I turn off the pump, let the water levels settle, then turn the pump back on again, it equalizes at that spot.

When the problem occurs, it's as if a blockage is preventing water from entering the sump at a rate to keep up with the pump, thus resulting in the heart attack water level of the tank. I think I'm going to investigate that theory a bit more today and see if I can figure this out. http://www.pushupstairs.com/images/emoticon/neptune/Animated/Angry/angry029.gif

[rolloffhill]

It may not be in the durso, but I'd bet its in the bulkhead or the lines going to the sump.

Grab a flashlight and look down the durso, if there isn't anything there I'd personally take a water hose to the bulkhead and turn it on blast to see if you can break something loose.

[kewlkatdady]

I couldn't agree more...


check an double check anything that has to do with returning water to the sump.

It may not be in the durso, but I'd bet its in the bulkhead or the lines going to the sump.

Grab a flashlight and look down the durso, if there isn't anything there I'd personally take a water hose to the bulkhead and turn it on blast to see if you can break something loose.

[tsunderl]

Ok... Floating plants can be the death of a standpipe! I put some java fern from the 135 in this tank just in case Momma Soluci decided to spit babies before we caught her. This way, the babies would have a place to hide. I thought the fish ate the JF since it disappeared rather rapidly. Well, took the canopy off today and felt around the top of the standpipe. Turns out, the evil stuff was clogging the holes in the standpipe! You wouldn't believe how well everything is flowing now that the holes are clear!

Yes, I'm a bit embarrassed... http://www.pushupstairs.com/images/emoticon/neptune/Animated/Stupid/stupid012.gif

[greeneyed]

Well, at least you found the problem without having to tear everything apart...

[kewlkatdady]

congrats on figuring out the issue.

[tsunderl]

Yep, yep, thanks. I'll be wearing my dunce cap for a while.

[rolloffhill]

Yay J-rod and me...:D

[tsunderl]

http://www.cartoonstock.com/lowres/mba0270l.jpg

[flamenco-t]

On a side note, I think with 1140 GPH pump ( I am assuming at full head to the tank) you may need bigger sump than a 30 Gallon.

DO you have an anti siphon break on the return pipe ? what if you're experiencing power loss one day ? you'll have all the water from the main tank down to where the return nozzle inside your sump...

stan

[AndrewH]

A "Durso" we were talking about above is a siphon break ;).

Actually, the 125 wet/dry I have is much smaller than 30 gallons & can handle up to a 150 gallon.

http://img.photobucket.com/albums/v463/Andrew_H/125wet-dry.jpg

30 gallon wet/dry for a 180 sounds about right.

I would assume the 1140 is the 0 head rating and with the head and all the fittings she's looking at about 900 gph.



Big congrats btw on finding the problem... could have happened to any of us (and probably has :brandy:)

[tsunderl]

Actually, the 30 gallon is perfect. It equalized at about 50% full, and that included the scour pads and bioballs. One of the first things I did was to unplug the pump to see just what would happen if the electricity were to go out and it fills to about 75% of the sump's capacity. Power has gone out since then with no problems. Thank goodness!!! Water stays nice and clean, fishies are happy, and no heart attacks. Perfect! The guy that had this setup before me did it right! http://www.pushupstairs.com/images/emoticon/extra3/17222.gif

And I wish y'all would fess up if it has happened to ya's so I will quit feeling so dumb!!! http://www.pushupstairs.com/images/emoticon/extra3/azaelia4.bmp

[bra8ndy8]

LOL I don't have a sump......but if I did............I WOULD HAVE ALREADY DONE IT!!

[tsunderl]

LOL I don't have a sump......but if I did............I WOULD HAVE ALREADY DONE IT!!

Get one, and DO IT!!!!!!!

Wait! No sump on that 300g??? How many filters you run on it??? :eek:

[flamenco-t]

A "Durso" we were talking about above is a siphon break ;).
)

I understand what a durso is...:rolleyes:

Think about it..your return pump will pump out water from the sump to the tank. I assumed that the RETURN pipe nozzle is submerged. IF for some reason you lose power to the pump. The Return pipe nozzle will continously siphon drain all the water from the main tank to the sump. UNLESS you have a hole drill to where air can enter the pipe and "Break" the siphon.

stan

[greeneyed]

I think I remember T saying there was a checkvalve in the return line somewhere?
But I may be mistaken. :confuzeld:

[tsunderl]

I think I remember T saying there was a checkvalve in the return line somewhere?
But I may be mistaken. :confuzeld:

This particular system doesn't have a checkvalve. And yes, the return line is submerged in the sump. It's kinda hard to explain, but water gets pumped back to the tank and goes through the two pipes that split off to both sides of the tank. There's four returns for the water to enter the tank, one at each corner. That's the short black thing you see in the corner. When power goes off, the water level drops to just below those water returns. Water stops entering the sump at that point because there's no more available. The water level in the overflow is below the holes in the intake pipe, so no worries there either.

[AndrewH]

I understand what a durso is...:rolleyes:

Think about it..your return pump will pump out water from the sump to the tank. I assumed that the RETURN pipe nozzle is submerged. IF for some reason you lose power to the pump. The Return pipe nozzle will continously siphon drain all the water from the main tank to the sump. UNLESS you have a hole drill to where air can enter the pipe and "Break" the siphon.

stan

Ok, now I see what you're talking about (and good point).

This particular system doesn't have a checkvalve. And yes, the return line is submerged in the sump. It's kinda hard to explain, but water gets pumped back to the tank and goes through the two pipes that split off to both sides of the tank. There's four returns for the water to enter the tank, one at each corner. That's the short black thing you see in the corner. When power goes off, the water level drops to just below those water returns. Water stops entering the sump at that point because there's no more available. The water level in the overflow is below the holes in the intake pipe, so no worries there either.

Stan is saying... if the power goes out and the pumps stops... water can travel backwards through the pump plumbing to overflow the sump unless you have a check valve inplace, an air hole/siphon break on the plumbing, or some other means of preventing this ;)

Though it hasn't happened before doesn't mean it won't happen in the future (Murphy's Law).

Do the return lines go below the water inside the main tank?

[greeneyed]

There's four returns for the water to enter the tank, one at each corner. That's the short black thing you see in the corner. When power goes off, the water level drops to just below those water returns. Water stops entering the sump at that point because there's no more available. Siphon should break when it gets below the return lines.

[AndrewH]

:) unless the return lines go to the bottom of the tank.

You'll have an empty tank and very wet floor when you get back from the movies/dinner/etc. ;)

[greeneyed]

Looking at the attached picture, the returns go just below the water level. Or just below the overflow.

[AndrewH]

After looking at her pictures again (downloaded them so I could zoom in), I see her returns stop an 1" or 2 from the top. :D

[flamenco-t]

yeah, that should be fine. As long as your sump can handle a water coming back down from the main tank before it reaches the siphon break, you should be okay.

Assuming your 30 gallon sump is running at 1/2 of its capacity ~ 15 gallon.
On a standard 180 with 72x24" foot print

It'll only take 2" of water level from the very top to fill up your sump. (72x24x2x.004433) ~ 15 gallon

So you can either place your return nozzle no more than 2" down from the main tank water level or install a siphon break no more than 2" from the top of the main tank water level.

I personally never trusted check valve. Just personal preference..

[tsunderl]

Siphon should break when it gets below the return lines.

yeah, that should be fine. As long as your sump can handle a water coming back down from the main tank before it reaches the siphon break, you should be okay.

Assuming your 30 gallon sump is running at 1/2 of its capacity ~ 15 gallon.
On a standard 180 with 72x24" foot print

It'll only take 2" of water level from the very top to fill up your sump. (72x24x2x.004433) ~ 15 gallon

So you can either place your return nozzle no more than 2" down from the main tank water level or install a siphon break no more than 2" from the top of the main tank water level.

The return nozzles are about two inches below the water line. The footprint on this tank is 48x36" and the sump fills to 2/3 of it's capacity when the pump is off and the water levels have settled. The return nozzles are angled, so when the water line gets below the top of the nozzle, the siphon is broke. That's about one inch below the normal water line. About an inch of the nozzle stays under the water line, even when the pump is off. Great design, IMHO. :D

[kewlkatdady]

with the angle on the return nozzles...
it sounds like a very good design and should present no issues with flooding.

Nice :werd:

[AndrewH]

x2

Yup sounds like you got it under control :hehe: