Struggling with sump choice vs space

[Thisisfine]

I've posted once about looking for anyone with a 90ish gallon corner set up to figure out what I can do for a sump. The abridged version is I will be picking up my dad's 92g corner and transporting it to my place (1.5hrs away). Since I can't easily run and do measurements, I've tried to use drawing programs online and 99% of the time an appropriately sized sump is too large of a footprint. See attached picture.

I'm worried if I get something that fits that it may not be sufficient to hold DT displaced volume if the return pump is off. BRS calculator says every inch of DT water is 4 inches so guessing three inches displaced it needs to hold 12g on top of what's already in it.

Would it be safe to cut plywood to the dimensions of the sump, place under sump since a couple of inches of each back corner would hang over the edge of the back of the stand. Stand is corner cylinder with both wall adjacent sides being 34 inches. I'm planning to have the stand roughly 4 inches from each wall. Is this asking for trouble or feasible? I'm looking at either the Bashsea 30x14x16 Bio Fuge Sump or Bashsea 30x15x16 Smart Sump (both are ~30g based on dimensions). In either case there will be overage. This is such a PITA.

And just to state - there already is a 20g with some kind of old-school mechanical filtration box in there and I swear the max water height in there was marked around 4 inches so I have no idea how the skimmer was working. I'd like to modernize this situation.

 

[FUNGI]

Feasible....yes.

 

[Thisisfine]

Feasible....yes.

but a regrettable decision?

corner tanks are beautiful with the depth but the space below *cringe*...I just don't see how an appropriately sized sump gets under there.

That's a list of sumps I looked at but most all will stick over the back edge of each side like the first attached picture. The trigger sapphire might be an exception but I'd have to do the dimensions in that draw program to confirm but it's also the least volume.

 

[FUNGI]

You could buy a used smaller cornet tank and use that as a sump....BUT, I dont think you will have any issues with the overhang

 

[Pistondog]

Use a check valve on the return pump and an audible high level alarm in the sump. This can be done with a tunze 3155 ATO, which uses a refil sensor and high level alarm. The check valve may fail and usually leak vs stay open. The high alarm will sound during the feeding pause to alert something is wrong.

 

[Thisisfine]

Use a check valve on the return pump and an audible high level alarm in the sump. This can be done with a tunze 3155 ATO, which uses a refil sensor and high level alarm. The check valve may fail and usually leak vs stay open. The high alarm will sound during the feeding pause to alert something is wrong.

Thanks

I like the idea of a check valve stopping backflow through the return lines in the DT; that saves some volume from the DT that goes to the sump.

For the audible alarm etc. that's going to require someone to be there, correct? I do not own a Tunze device so I'm not sure what it does beyond topping off the water.

 

[Thisisfine]

You could buy a used smaller cornet tank and use that as a sump....BUT, I dont think you will have any issues with the overhang

Yeah I'd probably just have to go with the overhang. I think a smaller corner tank is going carry significant height even if it meets the horizontal footprint, at least for ones I've been able to find dimensions for. A good idea though and would work if I could find something like a 20-30 gallon that wasn't 18-24" tall.

 

[Idech]

I like the idea of a check valve stopping backflow through the return lines in the DT; that saves some volume from the DT that goes to the sump.

I just had a custom tank built and I was going to have a check valve as well until many people told me they always fail and it’s a very bad idea to rely on them.

Can you get a different stand for the tank ? One that allows a bigger sump ?

 

[Thisisfine]

I just had a custom tank built and I was going to have a check valve as well until many people told me they always fail and it’s a very bad idea to rely on them.

Can you get a different stand for the tank ? One that allows a bigger sump ?

That's probably the gold standard here but I'm not sure I can find someone to build a wood triangular stand quick enough. If this was a fresh set up it wouldn't be an issue but this tank has been up for years with livestock, coral etc. I have no space to hold them, already have 2 QT's up with copper going and livestock in them for my 120g.

 

[Pistondog]

Thanks

I like the idea of a check valve stopping backflow through the return lines in the DT; that saves some volume from the DT that goes to the sump.

For the audible alarm etc. that's going to require someone to be there, correct? I do not own a Tunze device so I'm not sure what it does beyond topping off the water.

THe audible helps you monitor for check valve leak . For example when you pause the pump for feeding, the check valve should close. If it leaks, the water rises, the alarm would sound, alerting you to repair/clean it.

 

[Thisisfine]

THe audible helps you monitor for check valve leak . For example when you pause the pump for feeding, the check valve should close. If it leaks, the water rises, the alarm would sound, alerting you to repair/clean it.

Gotcha - makes sense now.

 

[Thisisfine]

Does anyone know if 92 corners are true quarter cylinders? IE if the sides are 34" then it's also 34" from back corner to midpoint of front glass?

It's a pretty poor rendering and I had to use a large circle to mimic the quarter cylinder curvature to estimate the space under the tank more accurately.

 

[Vivid Creative Aquatics]

May a custom sump would be a good options for this application. Assuming you could fit it into the stand - here's what I came up with

It could work, and would give you (limited) space for a skimmer and return pump, but if you designed it around your chosen pieces of equipment if could be quite nice.

starting at the top, you have your drain with a the bubble trap - filter sock,

That overflows into the skimmer chamber and that overflow to the return chamber with the return pump

If I'm reading your initial drawing correctly (~42 x 42") you would need about 6 inches of reserve height in this sump to accommodate about 22 gallons of drain back water, in the event the power is cut. basically the shape would hold about 3.5-3.8 gallons per inch of height.

If you made the sump 14in high, and set baffles to run water height at an average water height of 8in, it could work

 

[Thisisfine]

May a custom sump would be a good options for this application. Assuming you could fit it into the stand - here's what I came up with

It could work, and would give you (limited) space for a skimmer and return pump, but if you designed it around your chosen pieces of equipment if could be quite nice.

starting at the top, you have your drain with a the bubble trap - filter sock,

That overflows into the skimmer chamber and that overflow to the return chamber with the return pump

If I'm reading your initial drawing correctly (~42 x 42") you would need about 6 inches of reserve height in this sump to accommodate about 22 gallons of drain back water, in the event the power is cut. basically the shape would hold about 3.5-3.8 gallons per inch of height.

If you made the sump 14in high, and set baffles to run water height at an average water height of 8in, it could work

Thanks - that's a good idea. The scaling on that software is a little off. Effectively the side panels of the stand are 34x34". Each cube on that drawing software I've been using as 2"x2" space.

 

[Vivid Creative Aquatics]

Thanks - that's a good idea. The scaling on that software is a little off. Effectively the side panels of the stand are 34x34". Each cube on that drawing software I've been using as 2"x2" space.

OK - here's how I'm calculating water volume

34" x 35" / 462 = 2.5 Gallons per inch

462 is double the usual 231 you would use for calculating a squared or rectangle shape, since a Right Triangle is half of a rectangle shape.

So in this case, you would need an average reserve space of at least 8.8inches of sump height to accommodate the 22 gallons of back siphon water from the display tank

In that scenario The sump needs to be at least 16in tall and you would probably need to run the skimmer chamber at around 8in in water height.

With that said, assuming the tank is a similar size to the stand, you likely only need to accommodate for around 10-gallons of water, which would be the equivalent to 4in of drain back from the display (4" x 2.5 gallons). Even 6 inches would of back siphon would only be 15 gallons

That means you could get away with the original 14in sump Hight which is much more manageable from a maintenance stand point.

 

[Thisisfine]

OK - here's how I'm calculating water volume

34" x 35" / 462 = 2.5 Gallons per inch

462 is double the usual 231 you would use for calculating a squared or rectangle shape, since a Right Triangle is half of a rectangle shape.

So in this case, you would need an average reserve space of at least 8.8inches of sump height to accommodate the 22 gallons of back siphon water from the display tank

In that scenario The sump needs to be at least 16in tall and you would probably need to run the skimmer chamber at around 8in in water height.

With that said, assuming the tank is a similar size to the stand, you likely only need to accommodate for around 10-gallons of water, which would be the equivalent to 4in of drain back from the display (4" x 2.5 gallons). Even 6 inches would of back siphon would only be 15 gallons

That means you could get away with the original 14in sump Hight which is much more manageable from a maintenance stand point.

Nice, thanks for the explanation! That definitely makes sense with the math to back it up.

 

[Blue Spot Octopus]

Since this tank is set up, getting a sump to fit under the stand is one thing, getting said sump under an existing tanks is another.
I would save a bunch of Amazon boxes and see what actually works.
I would recommend a HOB skimmer and a HOB Reactor and call it a day.