Q&A: Keeping fish waste from clogging the sump pump?

From time to time someone tracks me down and asks a great question. I usually end up spending a minor chunk of time answering. Here's a recent question I thought might be of interest:

Hello Meg,

Thanks for 365 Aquaponics. I find it very informative for my future plans in aquaponics. I had some quick questions- How do you keep fish waste from cloggin up the sump pump?

Thank you very much! Regards, R

Here's what I do:

• I have relatively narrow pipes taking overflow water from my fish tank to my sump. This is not a good thing - if I were doing this over again, I'd make sure my drain to the sump was at least 2 inches in diameter. It's a solids lifting overflow, so it's supposed to suck the fish tank wastes out, and it does, to a certain extent.
  
  
• I don't have a swirl filter. This is also not a good thing. I really like the swirl filter in the HD Aquaponics youtube videos (episodes 28 and 29 show it, as I recall. I have all the parts to implement a swirl filter constructed out of a 5 gallon water bottle sometime soon.
  
  
• I have goldfish in my sump tank. They love to munch on stuff. So they keep the sump tank pretty clear. I also have a cover over my sump tank.
  
  
• My pump is slightly elevated. I originally put it on a 1 inch thick plastic mesh pad (repurposed the internal pump filter) because I wanted to reduce the noise of the pump. But elevating the pump does three other great things:

1. The plastic mesh isn't inside my pump. Leaving the plastic mesh filter inside the pump can leave you with a nasty slimy mess that you have to clean frequently. If you still want to have some waste filtration, put an external mesh bag filter over your pump.
   
   
2. The waste that is in the system falls to the bottom of my sump. Since the pump is ever so slightly elevated, chunks of gunk are less likely to get sucked into the pump.
   
   
3. If the water level in my sump tank gets low, the pump stops emptying the tank when there's still an inch or so of water in the tank. My goldfish who live in the sump tank are still able to get around and remain in water, so I'm pretty happy about that "accident."

Good luck!

Meg

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