Solid Waste Removal

[Wally Roderick]

Hi!  Just getting started, though I've experimented a little with FAP desktop system.  I've got 15 White Nile Tilapia that we will go through this weekend and start our breeder group of one male and 5-6 females.  They are going into a room in the garage 13x13-overly insulated, that backs up to my 8x16 greenhouse.  My goal is to learn how to do this slowly by incorporating 3, 110 gallon tanks for growout and working them into my greenhouse production through either raft, or mediabed/vermiculture.  Looking for any suggestions from anyone with success!  My immediate question to anyone who reads this is solids removal.  My 15 tilapia are in a 55 gal tank and I'm doing a 30% water change every 3-4 days. This will go down after I down size to 7 fish, but I want to know the best way to get the solids out - other than manual removal.  I put a second pump in and it pumps to a gravel filter - helps, but the pump isn't strong enough to suck up the solids.  My questions are too numerous for this post.  Any help!

[Cory Cramer]

If it's a 55 gallon aquarium, I would try an under-gravel filter. I've been trying to design a descent solids remove system for a couple years now, but I haven't quite got anything I'm completely happy with yet. Gonna start some trials this month on a new design, though. My goal is to eventually be able to run 6 months without a major clean out, but if I could get 3 or 4 months I'd be happy.

[Wally Roderick]

Thanks.  I haven't gone that route because I was told not to put down gravel to make it easier to see the eggs.  Are you raising tilapia, and have you found that gravel inhibits anything?

Cory Cramer said:

If it's a 55 gallon aquarium, I would try an under-gravel filter. I've been trying to design a descent solids remove system for a couple years now, but I haven't quite got anything I'm completely happy with yet. Gonna start some trials this month on a new design, though. My goal is to eventually be able to run 6 months without a major clean out, but if I could get 3 or 4 months I'd be happy.

[Cory Cramer]

I'm using goldfish. But if it's just a matter of seeing the eggs, you could always use a black gravel, or perhaps no gravel, and just set the trays in the bottom with nothing on top. I don't have any direct experience doing this, but it's the only way I can think of to at least separate and filter some of the solid waste. It's really hard to actually remove it from the bottom of the tank without sucking it out with something.

[TCLynx]

Solids move right on through my system fairly well using SLO drains.  I tend to pump much more than the volume of my fish tank per hour.

[Wally Roderick]

Work with me TC!  I'm kinda new to the business.  What are SLO drains and would they be compatible with 1 55 or 90 gallon tank?

[TCLynx]

Perhaps this diagram will explain better than words

SLO stands for solids lifting overflow.

Be sure to put a grate of some sort on the top and bottom of the SLO pipe to keep fish from swimming through it and finding themselves sunning on the gravel.

[Wally Roderick]

Thanks alot!  I'm doing some more research on this to get specifics.  I appreciate your help TC.