HELP! Overflow Flushing and vastly fluctuating water level

rodstar · #1 11/27/2007, 03:00 PM

So, let me briefly explain my set-up and problem and hopefully someone can help.

I have a 125g AGA with dual overflows. I think the returns are 3/4 inch and the drains are 1 inch. I am using Durso standpipes.

The sump and fuge are in the basement, so the water drains from the over flow into a T and into 1 1/2 inch spa flex down to the basement where it hits a tee to divert some to fuge and the majority to the sump.

The sump and fuge drain together into a T that goes into a BlueLine HD70 back into 1 1/2 inch spaflex and up under the tank where it T's out into the returns.

Here is my problem. I have the pump throttled way back via a ball valve (on the return after the pump) because if I turn it up, it drains the sump/fuge very quickly and the return from the tank ends up happening in fits and spurts like a toilet flushing.

The return is like so:
Turn up pump
Sump/fuge drain (but I have extra water pumping in to keep it from getting too low)
Drains run normally with low volume.
Water volume catches up and huge rush of water flows down into the sump/fuge (raising the level significantly because the rush is faster than the return.)
Then it slows way down, sump/fuge almost drain again and BAM! Loud flushing noise and another huge rush of water...

No matter what I do, I can not get this to stop or balance out. I have heard that I may have air stuck in the drain and not enough air getting in the standpipe so I should a) widen the air hole on the top of the standpipe and b) insert a long length of tubing into the standpipe until it hits the area that air gets trapped.

But, the dursostandpipe.com site says that the air hole is not the problem. http://www.dursostandpipes.com/FAQ/t...5/Default.aspx

Anyone have this problem and have a solution for me?

My flow is very low through the sump/fuge (though the tank is okay because of 2 Vortechs)

I hate to have the pump throttled back so much (ball valve is open probably 20% only). Or should I not worry about it at all because I have proper flow with the Vortechs.

Might be beneficial to know the following:
Sump = 29g tall with AquaC EV-180 skimmer and Mag-7 pump along with Phosban Reactor and Chemipure
Fuge = 35g tall

You can see pictures of the plumbing at: http://ocrd.blogspot.com http://ocrd.blogspot.com

Konadog · #2 11/27/2007, 03:31 PM

Well, one way you can figure out if it's the hole size, and figure out how much pump your overflows will handle is to take the caps completely of the dursos. Do this just to test, after removing the caps, turn your pump valve to open until you exceed what your overflows will handle, suck your sump dry, or until the flushing sound starts again.

rodstar · #3 11/27/2007, 03:43 PM

Oh, not a bad idea. I will try that when I get home tomorrow night. But, that may not solve the problem of air getting stuck and then burping out of the spaflex.

The plumbing run is 3 feet down, 12 feet horizontally through the joists and then down again. I am wondering if I have air getting caught in the horizontal run.

Konadog · #4 11/27/2007, 04:02 PM

That could easily be it! All plumbing needs to have a slope to it to keep the water from backing up anywhere, causing back pressure. Look at it this way, there always needs to be an unrestricted path for air to move, if the water blocks the air at any time, it's that time back pressure is created causing the flushing noise. The same goes for the "Tee" at the split to your sump/refugium. The drain should be angled. If you can't get the angles you need, you may need to go with larger drain line after your dursos, down to the sump/refugium to provide the air gap.

raddogz · #5 11/27/2007, 04:04 PM

What is the gph of the pump?

Overflows like what you described can handle roughly 600gph. The bulkhead is 1", but the actual drain pipe is 1.25" from within the overflow box.

I use an Eheim 1262 - roughly 1000 gph up 3' vertical height - no ball valve needed on my 120g

rodstar · #6 11/27/2007, 04:07 PM

My pump is a BlueLine HD70. It is rated at 1750gph. But, the head height is about 10 feet, plus a check valve, a union, a tee, etc.

I know I can't open it all the way, but I was thinking that I could get the ball valve opened at least 50%

I should also mention that the Spaflex for the drain and the return is 1 1/2 inches.

Konadog · #7 11/27/2007, 04:50 PM

Quote:

Originally posted by raddogz
What is the gph of the pump?

Overflows like what you described can handle roughly 600gph. The bulkhead is 1", but the actual drain pipe is 1.25" from within the overflow box.

I thought about that, one of the reasons I suggested pulling the caps and see how much the system could handle.

Quote:

Originally posted by raddogz
I use an Eheim 1262 - roughly 1000 gph up 3' vertical height - no ball valve needed on my 120g

Isn't a 1262 only good to 900 at 0' head, and can only push water to 11' 6", loosing gph on the way up?

FishTruck · #8 11/27/2007, 05:39 PM

I am plumbing my basement in a similar way.

My helper (Dad) who was a general contractor suggested that for the horizontal run, I make sure it slopes down by at least 1/4 inch per foot of horizontal run. This is the standard for drainage systems.

So, for an eight foot run, a two inch drop (at least). Should be easy to do, just by lowering your pipe hangers a bit. Also, watch out for the spa-flex making humps up and down. PVC might be easier to make sure the slope is right.

Just my .02.

R

rodstar · #9 11/28/2007, 12:02 AM

in hindsight, PVC would have been better but given the fact that I had almost zero access without cutting out the ceiling in the basement (not an option, just ask my wife...lol) spaflex was the way to go. I am sure it is making humps up and down. My only hope now is to run 1/8 inch tubing from the standpipe down into the spa flex return to see if it will hit the spot where the air is getting trapped and release it...

Any other suggestions to alleviate it in that space?

Pmolan · #10 11/28/2007, 08:29 AM

Head loss calculator

According to this, you shoud have 1500gph of flow at the tank. Each overlow is rated at 600. You should easily be able to handle that at full throttle.

rodstar · #11 11/28/2007, 09:18 AM

You would think...

So, here is the follow-up question: Should I care about getting more flow through the pump (sump/fuge)? I have 2 Vortechs in the tank itself for flow in the tank. I think I am getting enough flow through the two tanks in the basement, but I may try to measure it somehow...

Any ideas or thoughts on the question above?

Thanks for all your help!!!

H2OLUVSME · #12 11/28/2007, 09:42 AM

Quote:

Originally posted by Pmolan
According to this, you shoud have 1500gph of flow at the tank. Each overlow is rated at 600. You should easily be able to handle that at full throttle.

600+600=1200
1200<1500

This means the overflows cant handle the return if your calculations on the head loss are correct.

Quote:

Originally posted by rodstar
So, here is the follow-up question: Should I care about getting more flow through the pump (sump/fuge)? I have 2 Vortechs in the tank itself for flow in the tank. I think I am getting enough flow through the two tanks in the basement, but I may try to measure it somehow...

The lower the flow is, the easier the noise will be to control. Also, the more time water spends in your sump/fuge the more time your filtration has to act on it. Im shooting for something between 200 and 400gph for my new system. Itll be about 250 total gallons.

HTH!!

rodstar · #13 11/28/2007, 09:49 AM

Yeah, Landon, I think that is what I am going to go for...

I have been out of town for three days so i am anxious to go home and see how my cycle is going and weather my algae blooms have subsided. If the tank is looking better, that may be all the information I need...