what is wrong with my AP plumbing?

[Ryan Garlington]

After about 2 months of the water pumping fine, the pump is a bit weak and not pumping hard enough for the siphons to run right.

Are my pipes in need of a cleanout? Does the pump itself need cleaning? I don't have a filter in it.

[Alex Veidel]

Question....did you remove that little filter sponge on the pump? You'll want to take that thing off.

[Alex Veidel]

My thoughts exactly Jeff :)

Jeff S said:

I've been told, and have done this myself, to take out the mesh filter in the pump (if there is one). I've never had a pump problem since I did that. But it wouldn't hurt for you to get a 300-400 gph pump for proper flow.

[Ryan Garlington]

I temporarily fixed this problem by removing the screen from the outside of the pump. The snotty blobs were blocking the intake. Almost completely at times.

[Spencer Curry]

Is there a reason not to go for a very high gallon/hour pump? Is there a reason he should not get a 2000gallon/hour pump for his 140 gallon tank?

[Jeff S]

Way overkill. He would need to bypass a lot of the water. You only need to cycle the water 1-2 times an hour so a 300-400 gph pump would work depending on the head height you're working with. In my system I worry more about higher head height than gph because I have an in ground sump.

[Scott Fonte]

Others may disagree but below is my $0.02...

In my 25 years of experience keeping fish on both a hobby, excessive crazy hobby (90 tanks - 1500 total gallons), and commercial production the more turnovers in the FISHTANK per hour the better, anything more than 2 and less than 6 is practical.  Two turnovers is okay for light stocking density.  On the upper end it comes down to energy exertion by the fish - if they are swimming hard all day they are burning more calories and not growing as quickly - also species matters (e.g. trout vs. tilapia).  This does not always jive with the requirements of the hydroponic component.  This becomes more and more apparent as systems increase in size especially when larger tanks and/or higher stocking densities are utilized. I will use the example of a 3-tote IBC system.  

Fish Tank Volume - 250g --> x 3 turnovers per hour = 750gph

3 grow beds 100 gallons each w/ 40% void ratio cycling every 20 minutes = 300g x 40% x 3 = 360gph

Ideal fish flow is greater than growbed requirements.  There a few ways to work this.

1. Deal with lower flow through the tank and keep fewer fish.
2. Use Chop 2 system (IMO you send pureed wastes back to fish with this set-up)
3. Use two pumps and separate sumps.
4. Utilize a solid seperation system to clarify a portion of the water, treat with a separate biofilter and send the higher solids fraction of waste stream to beds at the required flow rate.

Of these I prefer #1 & #4 because I feel that either reduce fish or provide back-up biofiltration as a system component as good practice.  For small systems getting extravagent is not necessary as maintenance is manageable, but increases in size require increased "simple" complexity to keep things manageable.  Read "simple" complexity to mean passive methods whenever possible.

[Jeff S]

Good explanation Scott. Makes sense.