To Sump or Not To Sump

[johndirst]

Hello and thank you for your input.

I just joined this forum and it has inspired me to go big. I recently had set up my 125 and had blindly thought that it was a monster... I admire the commitment and passion that everyone on this forum has for the hobby... Anyway, on to the good stuff.

I recently bought a 380 gallon acrylic (8'x2'x3'2") and I am trying to determine how I will handle filtration. I have always used canisters, but I think I would like to tackle building a sump.

Some Info:
The tank has two overflows (one in each corner) each with two holes at the bottom (something like 1.5" and 2.5"), but the previous owner sealed the holes with a piece of acrylic and silicone. Also, inside each overflow there are 3.5" bulkheads just below the water line. Pictures of a rendering can be found here.

Eventually this tank will be stocked with Pacu (you may not like them, but I certainly do ), Barbs, Severums and a Bichir (about 8 fish in total).

Questions:

1. How difficult would it be to remove the acrylic blocking the overflow holes? I am afraid of damaging the tank.
2. I understand the two holes at the bottom of each overflow can be used to feed a sump, but then what are the large bulkeads for?
3. What size sump (gallon-wise) would I need to independently filter this tank.
4. Would it be better to run something like a 55 gallon sump AND a FX5 or Ehiem 2080?

Any help is much appreciated. I have some time before I set the tank up and I do not mind the DIY stuff (actually I prefer it ).
Also, about 5 months ago I picked up about 11 Liters of Eheim Substrate Pro (plus whatever is running in my current canisters) on clearance. In total it cost me about $70 for all of it! That will help offset the amount of media I would need to buy.

Thank you.

 

[Pharaoh]

1. Acrylic is easy to drill cut. It acts just about like wood except for the fact you have to keep it cool when working with it.
2. Bulkheads provide the seal for the plumbing running through the tank bottom.
3. Typically want to shoot for 1/4 to 1/3 of the tank volume, but I think a 75g would work well.
4. This is a toss up. Depending on the type of filtration on the sump, canister can provide an extra level of water polishing. with filter socks, I wouldn't think that they are necessary.

 

[johndirst]

Thanks for the info.

1. What I meant was can I easily remove the piece of acrylic that is sealed with silicone? I prefer not to drill it, but it may be the only way.
2. Stupid question on my part - The better question is what is the larger hole for since there are two holes at the bottom?
3. Nice, I think I can squeeze a 75 gallon inside the stand
4. I can always add a canister if the sump isn't keeping the water clean enough. I will probably run two pumps in the center of the 75 and have two intakes. This way I can power various return lines to kick up anything that settles on the bottom (should help with mechanical).

 

[johndirst]

Anyone?

Keeping my eye out on CL for a cheap 75 gallon

 

[polish]

Silicon doesn't stick well to Acrylic at all, you should be able to pop them right off.

I'd use the top large holes as my over flows and use the bottom 4 as return lines or just two and plug the other two. This way if the power shuts off the tank only drains down a bit, not all the way. Unless you were gonna do stand pipes but even still according to your drawing the holes up top are much larger so you may as well use those for drains.

 

[nugpuffer]

2. Stupid question on my part - The better question is what is the larger hole for since there are two holes at the bottom?

The larger hole is likely the drain and the smaller is for your return line plumbed to your pump.

As far as removing the acrylic, just use a razor blade to cut through the silicone. Do it carefully - as acrylic scratches easily.

 

[johndirst]

Thank you everyone.

This may be a silly question (or I may have the terminology wrong ):
The larger top holes are inside the overflow box and the smaller ones at the bottom of the overflow box... So if the bottom holes are used as the return and the larger hole is used to feed the sump filter, then wont the water just kind of keep flowing in and out of the sump filter since everything is isolated in the overflow box?
Does the question make sense, because I can visualize it my head

If I use the larger hole to feed the sump, I am inclined to leave the bottom holes plugged and just return to the tank outside the overflow box (there are two more holes in the top of the tank that are just outside the overflow box). Of course this does not protect me if the power goes out

 

[polish]

Well yes if you just let it return down at the bottom of the overflow. Ideally you'll want to put in bulkheads at the bottom and run piping up and over the overflow. Then have the output of the return spray away from the overflows into the tank.

If that isn't possible you can just run the return outside the tank and have it go over the back like a canister style filter for the return.

With all those holes drilled you have a few options.

 

[johndirst]

Thanks Polish!

I think using the larger top holes that already have bulkheads installed will work the best. I may install plumbing down the corner created by the overflow and the back of the tank on each side and have it run the entire bottom length of the tank with output nozzles along the way.

Prob gonna run two pumps as well which will feed the mentioned pipes along the bottom of the tank.

Thanks again.

 

[polish]

That would work well, just have one pump per side.

Also just drill a small hole just below the water line on the return line of both. A little water will come out but it won't affect flow much and if the power does shut off that hole will break the siphon once the tank drains down a little bit. This prevents the need for 1 way valves on the returns and is more fool proof to me.