Backyard Aquaponics
A place to discuss aquaponics

Thanks again all

GF, I have the pump on 110v right now, after the system is fully operational it will give me time to plan my 12v system more carefully. I may go to a 12v pump or stick with the one I have and run an inverter, if I go 12v I will use the 110 as a backup in case of a failure.

EB, I am going to cheat with the gravel washing, I have a pressure washer and a pickup truck

Del, I took Michaels advice and put some pressure treated lumber underneath the liner to support it, it can be filled completely with water with absolutely no distortion and should do fine with gravel.

Two minor issues so far,

1)My tank liner has developed a small hole somewhere and has become a little loose. The only purpose of it was to be a barrier against the zinc plated steel, so I'm not going to bother replacing it.

2)My pump can't feed all the beds at once, I tried to plan my plumbing to step down (from 32mm-feed to 25mm-manifold pipe to 19mm- valves and spraybars) in an effort to maintain velocity and flow. So I guess there are 2 choices get a bigger pump, or feed the right side bed from the drains of 4 of the totes on the back wall(the pump could handle it). I intentionally lowered the right bed 11" so drain feeding it shouldn't be a problem.
The pump is rated for 1450gal hour @0ft head and 1230 @5ft I have between 6-7 ft head depending on water level so maybe I have 1100gal an hour available. I thought of lowering the valve manifold 15" but don't know if it's worth the trouble.

-Stevo

Hey Stevo:
Doesn't treated wood have arsenic in it? I would wonder about that if so, if any water drips over the stuff it could end up with the fish?

http://www.des.state.nh.us/factsheets/bb/bb-19.htm

Dave, I had thought about that, but it shouldn't be a problem I used 2 pcs of 5/4x6 decking under each liner spaced 4 in apart, the siphon is dead center so if my seal starts to leak, it goes directly into the fish tank and not on the treated lumber. I used PT lumber because the liner sits flat on the lumber with no air circulation creating a potential rot area. I used std framing lumber on the back bench because the poly totes have nubs on the bottom allowing for an airspace.

-Stevo

im a bit confused i thought that the head was the hight that the pump could push to not the amount of water above the pump in the tank , that would make your head the height of the highest section of pipe and have very little to do with the level of water in the tank

Cheers
pete

good obs pete

The head which a pump can push the water to is measured from the surface of the water.. If you have a pump with a max head of 5 feet, it can push the water 5 feet above the water surface, whether the pump is 1 foot under the water surface or 6 feet under the water..

If your pushing up to 5 feet when the fish tank is full all is good, but as the water level drops in the fish tank, the pump will be doing more work because the head is increasing as the water level drops..

Looking at it another way....when the pump is idle (switched off) the water in the pipe is at the surface level of the tank and there is no energy required to keep it at that level....turn the pump on and..... I agree with EB's definition

thanks for clearing that up a bit EB, im not sure i quite understand why its so
my understanding is based on these points
head means the presure pusshing back on the pump due to gravity
the pump is moving the water from where i passes over/through the impelers

this makes me thing that even though the water in the tank is above the pump the pump will still have to fight gravity to push it beyond the hight of the water

but im am a trusting soul so if you say its so ill belive you, and like i said in another post im no engineer

Cheers
Pete

Pete think of it this way, if you have 2 tanks sunk in the ground, one is full and the other is half full. if you take a bucket and start scooping water out of the tanks by sinking the bucket all the way to the bottom of the tank and lifting it to ground level, you will use more energy to remove water from the tank that is half full because when the bucket is submerged it is weightless but as soon as it is out of the water it becomes heavy and requires more energy to pull it up. as the level drops you are lifting the bucket a further distance to get it to its destination.

-Stevo

good illustration. You a teacher?

No, acctually I'm a cabinetmaker that would love to be able to teach woodshop.

-Stevo

You can get headloss from friction in pipes and fittings

thank Stevo that makes sense now

Cheers
pete

you can get headlice from standing too close to someone with lice.

WASHING GRAVEL SUCKS! I got 2yds of gravel yesterday and even with the pressure washer it's taking a long time to get clean.