Sump design help please

[elusive_fish]

Hi, I'm changing my tank over to marine and while it's empty I'm going to drill/plumb it for a sump. I'm still pretty new to the ideas involved with sump design, so can you guys tell me if im on the right track?

My tank is a standard 4ft. I'm starting a low stocked FOWLR, and will add a skimmer at at later date (money pending!). I dont plan on having a large flow through the sump (only like 1000-1200 L), but provide flow through wavemakers instead. A rubber main is going to be the temporary sump until I get more sophisticated.

To keep things simple, I may just silicone single piece of glass across at a 45 degree on one corner, making a triangular overflow.

I still don't know what to do about the holes. I plan on having two stand pipes (type to be determined) for safety purposes and dont know what size holes to drill - or the appropriate sized bulk heads. I dont plan on drilling the tank for the pipe leading back from the pump in the sump, but just use elbows and put it over the top of the tank.

[Artem]

This is the best guide to setting up a marine sump that Ive seen so far :bounce:

[livingart]

maybe use 32mm bulkhead fitting from hansens products nz

think it requires a 40mm hole but get a fitting and check before drilling

pipe work from tank as large as possible to save having to redrill later if you need more flow through sump

[Ira]

maybe use 32mm bulkhead fitting from hansens products nz

think it requires a 40mm hole but get a fitting and check before drilling

pipe work from tank as large as possible to save having to redrill later if you need more flow through sump

I think if he's planning on running only maybe 1000lph through it then 32mm plumbing is probably overkill. I know bigger doesn't hurt anything but I was running about 3000lph through iirc 25mm.

[livingart]

fittings and hole saw will cost less too

[diver21]

25mm fitting requires approx 35mm hole

[spoon]

http://www.hansenproducts.com/products/thread/STF.htm

male tank fitting like the 1 i showed you

female has a thread other pipes can be fitted into

http://www.hansenproducts.com/products/thread/SFTFT.htm

hole size(note the 25mm is not on here for some reason)

http://www.hansenproducts.com/tech/thre ... ns/stf.htm

[livingart]

i found the recommended hole sizes too small

[spoon]

i found the recommended hole sizes too small

is that so allow a decent amount of silicon to seal it? ive heard the gaskets dont seal that well

[elusive_fish]

Thanks for the help. I see 35mm diamond coated drill bits on trademe for a reasonable price. It sounds like 25mm fittings will do me well. Spoon was kind enough to give me a tutorial on glass drilling and give me a 25mm bit and piece of glass to practice on, so hopefully it will help me gain some confidence to do it on the real deal :roll:

So what are your preferences on standpipes? 1 or 2? full syphon/durso/some other thing?

The downside to a triangular overflow is that it wont give me as much room for multiple holes - what is the mimimum safe distance between holes?

[livingart]

you will need to allow room for the flanges on the fittings

[Navarre]

Hi mate I still have that sump if you want to look at it

Nav

[David R]

I'd get in touch with a local tankmaker who has experience drilling tanks. Trying to save a few bucks with a bit of DIY could cost you a whole new tank if you get it wrong. Get the fitting first and he'll know what size hole to drill for it.

[diver21]

the size i said was from me just measuring the hole in the tank that was made for that fitting. has 2-3 mm play and fits nicely. and the hanson fittings come with seals so do you still need to silicone them?

[Ira]

the size i said was from me just measuring the hole in the tank that was made for that fitting. has 2-3 mm play and fits nicely. and the hanson fittings come with seals so do you still need to silicone them?

No, you shouldn't need to silicone them, but many people put a thin layer of silicone on each side just in case.

[livingart]

as Ira said

[elusive_fish]

I'll ask a couple local tank makers what it would cost for them to modify my tank, but I'm pretty confident I could handle the DIY if need be.

So do most of you run a second pipe for blockage reasons? I thought about doing one full syphon with a back up durso, but is it really necessary?

[David R]

Single pipe on all mine apart from the 1400L because of the flow and the lack of vertical drop between the overflows and the sump. Never had a problem with blockages, but I also don't keep plants [in my tanks at least], you could easily design the spray bar/drip system to be overflow-proof without drilling two holes.

[spoon]

there is all sorts of horror stories of blockages id say having a back-up isnt a silly idea to put it into perspective-- lets asy it blocks your tank will overflow- loss of saltwater could cost a bit to replace if using ASW then any damage done by the spill, then you have your sump running dry depending on the design of your sump this may or may not affect your skimmer and heater but your return pump wont like running dry and may crap out. then say you are at work and your heater is in the sump its a cold day and no heated water is making it to the tank livestock could be affected. and depending how far along you are the cost could be in the thousands.

id spend the extra $30 to get another hole drilled and another $25 for extra plumbing just as a precaution

[livingart]

i have never suffered a blockage

but always run a backup just in case

[David R]

Whats going to block it? Unless you're keeping lots of plants [unlikely with marine] I can't see it being a problem. I had a 14"+ tyre track eel sitting in the spraybar of my 6' tank running a grunty Laguna 7500 pump and it didn't overflow, just squirted a bit faster from some of the holes! Unless you plan on designing the plumbing/spray bar to JUST handle the normal flow of water to try to reduce the noise you'd have to have a pretty big blockage for it to overflow. I don't think there is enough water in the sump of either my 5' or 6' to be able to fill up the overflow and overflow the tank if the plumbing did somehow become blocked....

[livingart]

in marine, anenomes like to wander

usually get caught in a powerhead though

[spoon]

snails as well

[elusive_fish]

Thanks for all the input.

Another question for the fine folk here:

My tank is 45cm high. How high should the overflow glass be? And if I am running a 'herbie' how long should the standpipes be?

I'm pretty slow picking up on the concepts, but it sounds like I want one pipe to be running entirely submerged, handling the water flow in a syphon so that its silent. The other I should have somewhere between the top of the overflow level and the water level ie out of he water, but would come into play if the level was raised?

[Ira]

Also, the tank can't overflow if you raise the pump up enough, or size the pump chamber right so it doesn't hold enough water to overflow the tank. It's pretty straight forward to do.