Still confused about overflow boxes...

[JT101]

OK, first I want to thank everyone for all their assistance in my other thread about trying to "match" an overflow box to a sump return pump.

However, I've been studying what's going on with my system and I am starting to doubt my understanding of what's happening:

As I have been told and as per what I've heard, you adjust the water level in your tank by moving the internal overflow box up and down until the desired water level is achieved (again, this is a 46G bowfront with ESHOPPS PF-300 overflow and Deep Blue Triton 3 850GPH return)

Earlier I mentioned that I have 46" of head (call it 4 feet) and based upon the chart on the Triton's box I calculated about 450-475GPH at the actual return spot, but I forgot to take into account the fact that there are FOUR 90 degree elbows along the way, so if I add 1 foot per elbow (I think that's right :scratch then my "head" is really 8 feet! Weird thing is, according to the Triton 3 spec, the maximum head is 7.2 feet and yet my pump is working so, I don't know what to make of that...anyway:

OK, so I adjusted the internal box up & down until the tank level was where I liked it.

The thing is, when I look inside the internal box, the water level seems very low. So low that, as water pours in through the teeth of the box, there is a fairly high amount of bubbling going on and bubbles are being brought through the overflow tube and into the rear box.

The water in the rear box is also low. When I take out the foam "tubes" and the little vertical PVC pipe, the water literally gushes over the side of the small vertical acrylic separator plate.

I guess what I'm trying to say is is almost looks like the overflow box is too LARGE. I mean, if the box was "undersized", wouldn't it be doing the OPPOSITE? Wouldn't both the internal and external boxes flood (or at least fill up very high) with water?

See, I've never had an overflow box before so I just don't know what a correctly tuned one is supposed to look like

Any help would be GREATLY appreciated.

 

[Audi0s]

I think the box is too large for the return pump. Since waters not rushing over the edge and filling the box quickly, it drops the water level. You mgiht only be pushing out like 1-200 gph with that pump at head height. Hence the slow overflow. Get a mag 9 or 12 going on that and I think your box will work better. I had a similar problem when filling my sump with a mag 18 return. The tank and sump were full but when i turned the pump on it would drain the sump before really overflowing back down. I just needed to add more water. I doubt youll see a low water level at the box, and not in the return section of the sump, but its worth a shot. maybe add a little more water to see if it fills it up?

 

[skene]

ok simple... to understand your box.

1 if the water is going down too fast for the return pump to bring water back up you raise the box that goes inside the tank.
2 raise the box by positioning the slide nut.
Don't worry about what your return pump is putting out... just adjust the box to the desired water height.

ok... higher = less water to sump.
lower = more water to sump.

Easy? Don't overthink this. It's not rocket science.

 

[JT101]

ok simple... to understand your box.

1 if the water is going down too fast for the return pump to bring water back up you raise the box that goes inside the tank.
2 raise the box by positioning the slide nut.
Don't worry about what your return pump is putting out... just adjust the box to the desired water height.

ok... higher = less water to sump.
lower = more water to sump.

Easy? Don't overthink this. It's not rocket science.

Skene,

Thanks for your post. Let me elaborate a little on what I'm seeing. I can seem to very easily adjust the water level in my tank by either raising or lowering the internal box; higher box = higher display tank level, lower box = lower display tank level. That part is fine. What I think is "bad" is that no matter what position I adjust the internal tank, the water that is inside it at any given time is very low, perhaps less than 1". Because of this very low height, there is a large amount of air being sucked into the return U tube - in fact, so much that I fear I may lose suction if just the "right" amount of air gets sucked in.

If the U tube is taking water out this fast this leads me to believe that the return pump is not pouring water back into the display tank fast enough - or at least that's what it seems like

 

[skene]

Then what I would suggest doing is kill the siphon and start over again. You should remove enough air from the u tube so that there is only water flowing through.

If you cannot accomplish this by yourself you should look into this product.
http://www.saltwatercritters.com/inc/sdetail/1088/1433

http://www.youtube.com/watch?v=Jn6ZYYXpQmM&feature=related

 

[qy7400]

You can try raising the stand pipe or convert it to a mini durso, it sounds like you have the water levels mis matched; outside box water level to low. Have you tried a power fail after the adjustments to see if the water level equalizes?

 

[JT101]

Then what I would suggest doing is kill the siphon and start over again. You should remove enough air from the u tube so that there is only water flowing through.

If you cannot accomplish this by yourself you should look into this product.
http://www.saltwatercritters.com/inc/sdetail/1088/1433

http://www.youtube.com/watch?v=Jn6ZYYXpQmM&feature=related

Skene,

I use a small piece of 1/8 OD tubing to start the siphon so it's no problem for me to get it started. I found out what the real problem was: My Triton 3 wasn't strong enough after the 46" vertical head and 4 90 degree elbows. I bought a Triton 5 (1350GPH) and now the overflow box is running nice and full but not TOO full, and after playing around with the foam in the rear box I almost eliminated all the "toilet" sounds.

Thanks
John

 

[JT101]

You can try raising the stand pipe or convert it to a mini durso, it sounds like you have the water levels mis matched; outside box water level to low. Have you tried a power fail after the adjustments to see if the water level equalizes?

Yes, power fail allows the box to equalize but what was happening was the overflow U tube was just sucking water out faster than the return pump could replenish it, so I bought the Triton 5 (see other post) and all is well now