system turnover

[Michelle Silva]

Does anyone know how many times the water in a raft system should be turned over in a day?

I am in the process of figuring out what the best pump is for my system, whether to go with a bilge pump or sump pumps and what size. I would like a 3/4" outlet on pump. Of course, trying to use least amount of energy without taxing my pumps too much as well. One will be circulating constantly (raft beds) and one will be timed(verticals). I may be going solar, will know more later today.

My system specs:

three 4'x40' raft tanks (16" high, guessing the water level will be around 12"),think I calculated these tanks to hold around 1200 gal each

The center raft tank will have a pump that returns water to the highest fish tank (located approx 4' in front of raft) and then the fish tanks stair step down from each other(each having a 4"PVC waterfall into the other) with the fourth fish tank flowing into a buried 55 gal w/ pump that goes up to verticals (verticals gravity feed back to this 55 gal drum as well) and the pump also goes up and over to the outer two raft tanks. Returns down the center raft tank back up into highest fish tank(IBC tote).

four IBC totes fish tanks(cut @ 200 gal mark), water level may make it around 180 gal each.

Total water in recirculating system approx 4320 gal?

I haven't taken into consideration how much water will be flowing throughout the verticals.

There will be 350 vertical pots(approx 60 stacks) also on another timed pump with solenoid. I was originally planning to incorporate the IBC tops into the system as gravel beds, but have not done so at this time.

~Michelle

[Michelle Silva]

I'm now considering eliminating one pump and letting the last fish tank gravity feed into the two troughs and not making the verticals recirculating. I will still have a solenoid and timer off of the one pump that is in center trough and will split and go over to verticals. Seems it will make everything much simplier.

[Michelle Silva]

I also made a little dips down the entire center of the troughs to let gravity help them flow more.

[Michelle Silva]

The two outer troughs each have their own pvc input, but all flow out of the one center trough and into fish tank

[Michelle Silva]

HI Chris, Thanks for your reply. Could you please clarify. The the three 4'x40' troughs are right up against each other (share center walls), the two outer troughs will spill into the center at one end and return (in center trough) to the end closest to the fish tanks and be sumped up to highest fish tank(IBC tote). There should be lots of oxygen coming from the verticals and from the large pipes on each fish tank that will waterfall into the next(total of four) then flows into buried 55 gal that holds second pump needed for verticals.

[Chris Smith]

Aloha Michelle,
We have found that a minimum of 2 gallons of water is adequate to provide plants with enough nutrient. I am in the process of down sizing my pump to save on power. I an shooting for three gal/min. If your troughs are plumbed in series then you can use the 2gal/min, but if they each have their own feed then the pump will need to be large enough to supply each trough with 2 gal. I have two pairs of 40 foot troughs so I am looking for a total of 6 gal/min at the height that I have to pump up to.More flow is ok but it is better not to have excessive flow because the pumps and power are expensive.
You will need keep close watch on is the DO in your troughs. As you know it gets warn in Florida and the warmer the water gets the less DO the water can hold. You will want to test at each end of the troughs at given temperatures. It is possible you will need supplemental aeration in the troughs with higher water temps. UVI has to do the because their water is in the 80's
I do not know anything about vertical requirements.
I will get some pics of my sprouting table up in the next day.