New tall sump design considerations.

[kevyeah]

Hi all, long time lurker, first time poster!

I have recently installed a 180g mbuna cichlid/turtle tank, and figured the water butt on the other side of the wall - outside - could turn into some form of tall sump system to compliment the two Rena XP4s and Ehiem 2080 on the other end of the tank; but cant decide on the best layout within the "sump" to avoid flooding the tank in the event of the drains blocking, whilst still utilising the full height of the water butt for media.

I have a "Jebao - DCT6000" 6000l/1320gph pump which I plan to site half way up the inside of the sump (to limit the amount of water it can pump back to the main tank in the event of an intake blockage) with initial plans for pot scrubbies underneath (filling the sump about two feet high) and floss/mech filtration above.

I have dual 40mm (approx 1.5") drains from the tank which will drop in via gravity through the sumps' lid, with one 25mm (1" approx) return you can see mocked up at the upper left of the sump in the pics below. The one other 40mm drain you can see exiting the bottom of the tank is for general water changes/drainage/anything direct from the tank, just in case its ever useful. Total sump capacity is around 30 or 40g.

So.....
Keeping the pumps' intake half way up the sump to limit any main tank flooding in the event of a drain blockage, does anyone have ideas/suggestions as to the best way to fill the sump to maximise its efficiency, without water simply flowing in through the lid, through filter floss and straight back out via the pumps output?

Any other thoughts/critiques greatly appreciated, as its my first foray beyond canister filters,

Cheers,

 

[duanes]

I have used barrels as sumps many times.
I put them just to the side of the tank to allow room for maintenance.
If you have a proper overflow system near the top of the tank, the water in the sump will not overflow. The level will be determined by gravity and the power of the pump. The pump will return water to the tank as fast as it falls to the sump.
Pic directly below during a water change

normal

As you can see, I use filter socks for mechanical, some ceramic rings, and use the sump mainly as a place to put equipment such as heaters, and pumps.

 

[kevyeah]

Thanks for the reply - my concerns were more around the main tank flooding actually (as the sump is outdoors that doesn't really concern me, should it ever happen, and I will drill emergency drain holes near the top of the sump anyway.)

I have two drains at the top of the main tank, probably draining to the sump via 90degree elbows with guards over the top (and no overflow/weir, at least at the outset.) If they were to block, the main tank could quickly overflow, unless the pump in the sump is sited higher up within the sump - I've calculated the main tank can hold 11inches worth of sump-water before that happens, so the pump will be around 10 inches from the max water line in the sump, hence my design/sump water flow considerations/limitations.

I guess my issue is that I don't want to fill the lower half of the sump with bio media, only for water to not flow that low as it is pulled down into the pump. Does that make sense?

 

[duanes]

This is true, if the drain openings on the tank get plugged, the tank will overflow.
This is why when I drill my tanks these days, I always go for a hole (or 2) the fits 1.5" PVC.
I had tanks with smaller hoes, and found they are tooeasily plugged with plant matter, a dead fish, or even a bunch of snails.

a 2nd overflow, a bit higher than the main one is always a good insurance policy.

 

[kevyeah]

Well ive got a pair of 1.5" PVC drains, I guess I simply wanted another form of insurance policy - otherwise I could site the pump at the base of the sump, and I would have no problem.
....this still doesnt solve my general sump design/water flow issues though