jbrinker
New Member
I'm planninng out my sump, and have run it through in my head a number of times. I know there's a way to calculate the sizes and positions of the return chamber, suction line, etc so that the whole system is "fail safe". I.e. due to power failure the sump will never overflow, and due to clogged return, the return chamber would run dry (possibly ruining pump) before floodding the living room.
My thinking, without using too many real numbers, goes like this:
Display tank: 55gal, 48x12x24" deep. Area = 576 sq in, so each 1" of depth = 576 cu in.
Overflow (not drilled) and standpipe/drain (assuming its full of water, sump will be in basement ~ 10' below top of display tank): overflow: ~10 cu in, 10' of 3/4" hose = ~48 cu in.
Scenarios to consider:
Power outage- tank drains to bottom of overflow, then stops. Drain hose drains. Sump needs to be deep enough to absorb all that. This seems simple enough, just build the sump so that its about 1/2 full (depth wise) normally. Oh, gonna use a 30 gallon tank for a sump/fuge/return (submersible pump) combo.
The scary one - return gets clogged or siphon break.
Seems as though, to be safe, Id have to place the return pump such that it would start to suck air before the main tank overflows. But I want to try to calculate the appropriate sized return chamber (I guess I can always just make it a little too big, then vary the height of the return pump).
So, lets say I set the overflow level in the tank at 1.25" below "flood stage". And I'll build in a .25" safety margin, so figure 576 cu in of water "above" the return pump intake.
If I subdivide the 30 gal (12 x 36 x 18?) into three chambers, and I make the return pumping chamber 12 x 12, (=144 cu in per inch of height) I can have about 4" of water "above" the bottom of the intake pipe. Any more than this, and Im asking for a flood in the event of a catastrophic failure in the return line.
So, in designing the "fuge" and skimmer chamber, what shall I do? Am I missing something here? Ahh, yes I believe I am... In the event of a siphon break, all the water from the drain line will dump into the sump. And add to the "height" of the water available in the return chamber... Thats an additional ~55 cu in, or about 1/3 of an inch.
So, once running, my best bet with a return chamber of 12 x12" is to make sure the "normal" (full) line is no more than about 3.5" above the point where the return pump sucks air - to have a truly fail-safe system.
(And, yes, I do plan on using a float switch as well, to hopefully save the pump, but a new pump is cheaper than a new living room and a divorce
What are the common thoughts of the sump/fuge design? I was figuring a central "sump" chamber with the skimmer (prolly like 8"x12"), a 12x12 return section, and a 16x12 fuge with live sand/rock/pods/macro/possibly cleaner clams.
So, 12x16 fuge, fed by partial (ball valve) raw drain water, overflowing into the central sump. Remainder of drain water directly into sump. Sump in center, overflows (bubble trap?) into return chamber where submersible return pump lives.
Thoughts on this, my calculations, and any other fail-safes? I'd like to use hose for the drain and return lines. I want to avoid kinking tho - any types better than others? For the return I plan to make an "L" shaped piece of PVC, which will return water all across the back of the tank (behind LR) through a series of holes in the pipe.
Jeff
My thinking, without using too many real numbers, goes like this:
Display tank: 55gal, 48x12x24" deep. Area = 576 sq in, so each 1" of depth = 576 cu in.
Overflow (not drilled) and standpipe/drain (assuming its full of water, sump will be in basement ~ 10' below top of display tank): overflow: ~10 cu in, 10' of 3/4" hose = ~48 cu in.
Scenarios to consider:
Power outage- tank drains to bottom of overflow, then stops. Drain hose drains. Sump needs to be deep enough to absorb all that. This seems simple enough, just build the sump so that its about 1/2 full (depth wise) normally. Oh, gonna use a 30 gallon tank for a sump/fuge/return (submersible pump) combo.
The scary one - return gets clogged or siphon break.
Seems as though, to be safe, Id have to place the return pump such that it would start to suck air before the main tank overflows. But I want to try to calculate the appropriate sized return chamber (I guess I can always just make it a little too big, then vary the height of the return pump).
So, lets say I set the overflow level in the tank at 1.25" below "flood stage". And I'll build in a .25" safety margin, so figure 576 cu in of water "above" the return pump intake.
If I subdivide the 30 gal (12 x 36 x 18?) into three chambers, and I make the return pumping chamber 12 x 12, (=144 cu in per inch of height) I can have about 4" of water "above" the bottom of the intake pipe. Any more than this, and Im asking for a flood in the event of a catastrophic failure in the return line.
So, in designing the "fuge" and skimmer chamber, what shall I do? Am I missing something here? Ahh, yes I believe I am... In the event of a siphon break, all the water from the drain line will dump into the sump. And add to the "height" of the water available in the return chamber... Thats an additional ~55 cu in, or about 1/3 of an inch.
So, once running, my best bet with a return chamber of 12 x12" is to make sure the "normal" (full) line is no more than about 3.5" above the point where the return pump sucks air - to have a truly fail-safe system.
(And, yes, I do plan on using a float switch as well, to hopefully save the pump, but a new pump is cheaper than a new living room and a divorce
What are the common thoughts of the sump/fuge design? I was figuring a central "sump" chamber with the skimmer (prolly like 8"x12"), a 12x12 return section, and a 16x12 fuge with live sand/rock/pods/macro/possibly cleaner clams.
So, 12x16 fuge, fed by partial (ball valve) raw drain water, overflowing into the central sump. Remainder of drain water directly into sump. Sump in center, overflows (bubble trap?) into return chamber where submersible return pump lives.
Thoughts on this, my calculations, and any other fail-safes? I'd like to use hose for the drain and return lines. I want to avoid kinking tho - any types better than others? For the return I plan to make an "L" shaped piece of PVC, which will return water all across the back of the tank (behind LR) through a series of holes in the pipe.
Jeff
