Sumps for freshwater

[gzeiger]

I bought a 60 gallon tank off Craigslist recently, and it came with a sump-style filtration system originally designed for saltwater, if a bit poorly. At the moment it's just a small (maybe 5 gallon) acrylic tank stuffed with bioballs, which may explain why his fish died and he got rid of it. I could just buy a real filter, but since I have a very nice overflow box and pump already, and there are certain other advantages to having a sump, like breeding scuds in it, I was thinking I might adapt the existing system.

I'll have near-infinite space in my garage for this setup, so I could get a 10 or 20 gallon glass tank to replace the acrylic thing, or place in series with the acrylic tank, but I need some advice on how to go about turning the spare tank into a filter. At the moment I planned to just add some pot scrubbers to the bioballs and have the sump tank be full of plants to soak up nutrients. I could easily get Azolla, Elodea, Anacharis or Ceratophyllum that I think should be suitable. Is there anything else I should do or know? I may also add a bunch of oystershell and/or aragonite for pH/GH boost.

 

[jsoong]

I think you have a nice plan for the FW sump .... a few refinements:

1. Get as big a sump as you can house ... it doesn't have to be glass, a see through rubbermaid tub works well & costs less. If you are considering a planted fuge, I would get at least a 20 or 30 gal for the sump. <40 or 50 gal is even better.> You need a fair bit of "head room" in the sump to hold the water coming down from the display in case of pump/power failure. In a small sump, this might mean 10-12" of space, and that doesn't leave much water depth for the plants. With a big sump, you might need 4-5" of head room for the same volume, so you can have a nice foot or so of water for your plants to grow in.

2. You can use the existing 5 gal sump as your media compartment. If you have it above the new sump, you can just drill some holes at the bottom (or install a bulkhead & drain ... quieter) to let the water out. Basically, I am thinking of having the display drain into the 5 gal, have the water percolate through the bioballs/media, then drain out by gravity into the sump.

3. you can get easy plants for the fuge (like duckweed or hornwort) ... or grow green algae. Soft green algae is just as good a nitrate sponge, and prob. easier to grow. But then, plants look better ....

 

[gzeiger]

How would you keep the algae out of the pump? Algae would be ideal for my purposes since it's the best scud food, and could be combined with the Azolla, which is just a beautiful plant, but it seems like it would get sucked up in the pump and spit out in the main tank.

 

[asudavew]

I'm in the process of setting up a "new" FW tank as well.
And mine came with a sump too...

So, I'll be watching this thread closely.

I like the advice so far!

Thanks

 

[jsoong]

I have a pre-filter on the pump intake. It keeps out most of the particles floating in the sump. I would suspect that it would keep out algae bits (not green water, unicellular algae, but that is not what you want to cultivate anyway.)

Another solution is to have a separate compartment to house your pump. The SW people usually separate the fuge from the return pump with a divider to keep their critters in the fuge. Maybe that would work in FW as well.

 

[gzeiger]

The point of the critters is that they should get sucked up in the pump from time to time where they will get eaten by the fish. I was thinking that with floating or rooted plants you could have the last chamber with the pump receive flow from beneath the surface only, and keep the plants out that way.

 

[gzeiger]

Here's the plan so far: his sump tank, which is more like 3 gallons now that I look at it, will contain the gallon or so of bioballs it came with in a wet/dry sort of setup, and it has some space left over in a second chamber. I'm not sure what to do with that. I've picked up a 50 gallon Rubbermaid tub for the main sump, so I'm thinking I'll have an outflow from the mini-sump pouring into a standpipe of 3" PVC stuffed with pot scrubbies, so the flow into the first chamber of my sump will come out at the bottom and spill over an acrylic barrier. I plan to fill that first chamber with crushed oyster shell to provide a permanent pH buffer and water hardness since I plan on keeping crayfish in the main tank. The second chamber will take up most of the tub, and will have Azolla and Anacharis for nutrient uptake but otherwise I don't know what to do with it. I may raise cherry shrimp or something in there. The last chamber will be separated at the surface by another sheet of acrylic so the water flows underneath it, holding the floating plants where I want them, and will also house the return pump.

Anybody have any ideas what I might do with the remaining 2 gallon space in the first tank, or other things I could add to the big sump tank?