Can a 30g acrylic hex tank make a decent sump?

knifegill · Jun 8, 2010

Any reason to not use a hex for a sump? I'm picturing a deep basket of filter floss on top of about a foot of sponges and maybe a little lava rock with a pump in a cage (or maybe a small upright box to avoid returning any stray bits from the bottom?) at the bottom.

I'm mostly wondering about the lack of a separate pump chamber and if I'm alright without it. I have a good overflow box and strong pump, so that's all kosher. I suspect I'd keep the water level somewhat low in case of power failure. Anybody else using a hex tank for a sump? Input?

polish · Jun 8, 2010

Old setup behind my 200g. Worked fine for me for a year or so. I just changed it up recently and now use a 25g Rubbermaid under the tank instead so I could have more room behind the tank. Otherwise I would have left it as is...

That is a 50g Hex btw...

3 drawer plastic tote deal from Lowes/Wallyworld/etc was the Bio Chamber. Bottow drawer was gone. Middle was scrubbies and top was a mix of stuff. (Rings, Floss, Bio Balls, Foam Pads, etc)

knifegill · Jun 8, 2010

Nice. I was thinking of a drawer tower, but the tank only has a small opening... Good to see it works out, though. I notice you wrapped a sponge or something around the end of that hose. Is that the uptake back to the tank? If so, why not put filter floss on top of the tower and catch particles there?

zennzzo · Jun 8, 2010

other than the foot print, and servicing hassles, I can not see any problem...

cut some PVC pipe, to hold some egg crate up off the bottom, and put the pump down there with a sponge on the intake...only thing about this type of set-up with the pump on the bottom, is unless you put the media in bags, you'll have to take it all out piece by piece, to get to the pump...

knifegill · Jun 8, 2010

with a sponge on the intake

Shouldn't the mechanical filtration take place before the biological?

Good points about maintenance, too. I think I might find some smaller stacking boxes that I can tip and remove rather than a drawer set. My local dollar stores are riddled with all manner of plastic boxes and containers, baskets, etc.

polish · Jun 8, 2010

Yup, Mechanical is before Biological BUT you want a sponge over the inlet of the pump either way. Even though you won't see much of anything in the sump floating around stuff still makes it's way through. The sponge and scrubbie prefilter combo got cleaned in the sink weekly. It isn't there to provide any real filtration. It's just there to stop the pump from sucking anything up and damaging it. I also kept some guppies in the sump, it kept them from being sucked up too. It would be nasty brown by the end of the week usually. A lot of pumps have a sponge over the inlet for when you run them submerged. IE; both my ViaAquas, however this Quiet One 3000 did not. Just some sort of plastic deal with holes it in, I didn't like that because it wouldn't catch anything. It just stopped anything large from being sucked into the pump. So I opted to run the fitting you use for external use so I could put a pre filter over it. I could have mounted a sponge right to the pump but being on the end of the hose it just slid on/off for weekly rinsing. I used the sink sprayer to completely clean it out - yes I am aware it kills everything but I wanted it completely clean each time. And like I said it was just there to catch any last particles and to protect the pump, all the real bio was up in the tote.

knifegill · Jun 8, 2010

That makes a lot of sense. I will cover the intake, then.

I cracked the baskets trying to put them into the tank. Being round and acrylic, can I just cut out some of the top plastic as long as the rim is left in place? It won't be full anyway, so I'm thinking it would be fine.

Instead of having to buy floss or a huge pad, can I soak an old plain t-shirt in vinegar to remove any soap residue and fold it up as a pad?

knifegill · Jun 8, 2010

I've discovered that acrylic is more likely to crack in a straight line than accept a cut from a pair of tin snips.

After the first cut into the top exploded in my face, I went ahead and scored my next cut deeply with a razor knife to guide the crack. It worked and now I have a considerably larger opening.

I'm still iffy about how high to raise the media, but I think the pump and lava rock are doing a fine job for now. Here are some pics of what I would like to call a 'rough draft' but is realistically more like a 'jagged excuse' for a sump. I will add more sponges, etc. later.

I don't have floss yet, so the water is just falling through the screen onto the pads and then down onto the scrubbies. I'm going to run this for quite awhile before thinking of hooking it up to any of my tanks. I have no idea what's going to bleed out of those ghetto plastics. But I figure after a few weeks of flow and water changes with hot water (pump freeze-up?) it will be clean enough to use without worrying too much.

Now, with my goal being weekly water changes with only monthly filter maintenance, I'm really not too keen on blocking the pump with a sponge. I'm being very wishy-washy on this. Red checker, black checker. But I feel that if my mech filtration is functioning properly, the usual powerhead cone ought to be sufficient.

And I think I might need to replace the baskets with more walled containers to direct flow downward more effeciently. And then part of feels that as long as the mech is good and the bio is wet, all is well.

Remember those tubes you spin to get a whistling sound?