Backyard Aquaponics
A place to discuss aquaponics

I've read the advice and most of y'all will probably think I'm crazy or this is doomed for failure, but I won't know till I try. So please help me sink this boat.

I am going to go with media filled grow beds. 6 4x40 troughs made into 30 separated 4x8 GB

https://docs.google.com/drawings/d/1jwvWyPRgFas5MJK4RdUQfWz6ZmW5Ald7qrcvBbj8CHI/edit?usp=sharing

https://docs.google.com/drawings/d/1i41zDDPqvSXuXo5cMlWNcupYJblN2HrLebLo9gne5D0/edit?usp=sharing

If I had two pumps, each one feeding three GB at 4x40 that is 480 sqft. Which will need 480 lbs of mature fish, which requires 3600 gallon FT. Im thinking the sump tank will be 24 x 4 x 3 ft or 2115 gallons.

or one pump feeding 960 sqft GB. 960 x 7.5 g/cubic ft = 7200 gallon FT (1440 fish). I know a larger tank or tanks of water makes things easier. so im thinking three tanks at 2943 gallons or 8829 total gallons.

The pump or pumps would need to raise the water 6 ft plus carry it 40 ft.

I plan on using auto siphons and the water to be running constantly. If that is the case how best do I calculate the GPH needed for the pump to fill each bed once per hour? As it starts to siphon Im thinking of either cutting holes or the top half of a large tube for the water to run down to the sump tank.

These numbers are based on the 1:1 ratio. When switching to a 2:1 or even 3:1 ratio, I assume its better to increase the number of GBs rather than cut down on the size of the FT, thoughts on this?

please let me know if I am doing this wrong or need to add anything, thanks

Adding to this I would say that I'll probably stick to a single pump and need to add sequencing/indexing valves to rotate, so the sump tank would need 6x4x8=192sqft x 7.5 = 1440 gallons plus whats a safe amount? Another 500-1000g? Or will I not need the indexing valves since it seems like the beds will be emptying a staggered times?

I'm not going to mince words here....sorry.

This is a bad design.

There is no issue with having each of these fish tanks feeding one large growbed and you will be grateful for the simplified plumbing. You can still use one large sump tank or one sump for each fish tank... you will have to decide which to choose.

It will be much simpler and cheaper to pump straight from the sump/sumps to the fish tanks and have a solid lifting overflow drain onto each big bed. This will avoid the expense and mental anguish of trying to balance flows among the individual grow beds. If you go the more complicated path you will hate yourself.

Depending on your choice of sump or sumps you will need either one or three pumps if choose "sumps" you should select pumps that will exchange the water in the fish tanks once per hour. This is pretty standard advice. If you go with "sump" you should select a pump large enough to exchange the water in all three tanks every hour and divide its output between the three fish tanks or have three individual pumps, one supplying each tank.

Which ever way you go, the water in the fish tanks needs to be rotated every hour.
And the water returning to the fish tank needs to be cleaned and oxygenated.

You will still need a way to set flow into the growbed so that siphons trigger reliably usually a ball valve is sufficient. You will also need a way of stopping the fish tanks from overflowing and you can accomplish this with a second overflow on the fish tanks This overflow takes water from the top of the fish tank where the water is clean and sends it back to the sumps/sump. It will need to be above the outlet for the solids lifting overflow'

The other alternative is to have a way of throttling or diverting water from the pump on its way to the fish tank. I would not choose this option. I would choose the first because done correctly you get increased aeration and tanks circulation.

Its cool, you could call it a unusable piece of fish waste if you wanted to as long as you had some advice back, which you definitely did, thanks.

The reason I started with the pump pushing the water to the fish tank and the grow beds was so I could put valves at the beginning of each to shut off water to one in the case of maintenance needed on half and I could keep water running to the other half.
[youtube]http://www.youtube.com/watch?v=p9nP9O26mBg[/youtube]

I definitely see where your method would be simpler and save energy, and there is totally enough drop for gravity to take effect. Did you say though you wouldn't divide the grow beds into 4x8 sections but still have multiple siphons? For sizing the sump lets say three, for two GBs each at 4x40. It will need to hold 320 plus gallons, any good estimates out there for extra volume of the ST to keep ratios safe? And if the GBs had 960sqft, going to the 2:1 ration. We'd need 3600 gallon FT, plus some extra power would put it at 4680 gallons need to be pumped an hr, divide that by three is 1560 GPH per pump. A little more reasonable, right?

See this thread. It may be of some use.

viewtopic.php?f=13&t=22202

That right I wouldn't divide the growbeds and one siphon per bed will do it just needs to be able to out pace the speed of the water entering. Because its a big bed a larger siphon say 20mm should do and you can regulate the siphon trigger with the ball valve where water enters the bed.

Whether multiple or single sump the volume will need to hold enough water to handle, at a minimum, 50% of the volume of the growbeds it/they are servicing. The 50% number is because most growbed media will take up around fifty percent of the volume of the growbed you need to supply the rest from the sump and still have sufficient to cover the pump in the sump.

I would not count on growbed flood timing to even out the sumps volume being used at any one time. Murphy's Rule tells us that at some point all the beds will all be full at the same time.

I think your numbers are close but we could go over them again later for clarity as your design ideas coalesce.