Backyard Aquaponics
A place to discuss aquaponics

I'm starting into the initial construction and from researching further I'm debating my originally planned pump / index valve setup.

I'm going to be using a Flood and Drain setup using 3 IBC totes. My original thought was connecting all 3 tote FT's in serial to ensure a large enough water supply, a single external pump (ease of maintenance), and an indexing valve to flood one GB for 20 minutes at a time, then index to the next bed for 20 min, etc.

But knowing that pumps are happiest not stopping/starting over and over, I was thinking a 24/7 runtime on the pump necessitating an automated 'trigger' for the index valve that didn't require stopping / starting the pump (like this: http://www.aquaponiclynx.com/automated- ... th-control)

But as I start adding up costs and seeing the complexity potentially rising, am I better off with a separate pump for each FT and a simple / dumb timer that triggers the pump for 20 min each hour? I am concerned about costs, but equally about limited / ease of maintenance.

Experiences appreciated!

Why not use auto siphons? They are cheap to make and completely reliable when tuned. You can bury one IBC as a sump and use a standard chift pist design.

Sequencing valves are expensive and prone to failure if you don't filter solids upstream.

Auto siphons would run the tanks down lower so might not be the best option. You could do a mix or auto siphons and Constant Flood or just Constant Flood and forget about the fluctuation issue. Using CF there would only be the fluctuation due to evaporation and transpiration of water. The pump would run 24/7 and you could have a smaller sump or tank without the fluctuations. You could also add grow beds without changing the sump size because each grow bed would hold the water it contains if the power fails (although at some point you'd probably need to due to pipes or other reasons). Have a look at the BYAP trials thread where growth in Timed Flood and Drain, Siphons and Constant Flood systems are compared for a year http://www.backyardaquaponics.com/forum/viewtopic.php?f=1&t=8621.

I like the simplicity of the F&D, and had read about the results of the linked trials which reinforced that choice. I'm comfortable with a F&D setup, and would prefer pumps over auto siphons given I have less reservations about continuing operation if I'm not around for a day or two.

That being said, any thoughts have regarding the question on a single pump w/ automated index valve vs a pump per FT w/ a dumb timer would be appreciated.

Thanks!

I'd look at the electrical costs over time and you probably should consider redundancy as an advantage even if one system failed the others might still continue (depending on what fails of course). If the separate pumps are all on separate AP systems then you have a quarantine system if you need it. You can still separate the fish by size or take one system down for cleaning if you want. It will cost you in plumbing, hard to say how much compared to the index valve setup.