Backyard Aquaponics
A place to discuss aquaponics

Hey everyone, Im messing around with the idea of using a conical bottomed tank, here is the diagram

http://www.dura-tech.ca/files/pdf/conical_tanks/35CB64.pdf

So id like to be able to figure out if enough pressure is being applied to carry water 40 ft horizontally. The GB height will be 3 ft, so lets first assume the bottom nozzle is above this? What about below this?

If it is capable of carrying the water that far, what is the rate to know the GPH of the water from the sump to the FT to keep a safe level.

Any useful info when it comes to using these type of tanks?

Basically if the top of the water in the conical tank is higher than your grow bed then the water will make it the 40 feet to your grow bed. Water seeks it's own level.

We usually aim to turn over the water in the Fish tank once per hour. You have to factor in the height from the top of the water in the sump to the highest point you're pumping to (this is called the head height). Most pumps offer a chart or graph telling how much they can pump at a given head height. Find one that pumps the volume you need plus a little extra because manufacturers sometimes over sell their product. Looking for an efficient, durable pump, that may cost more initially, will save you enough to pay for the better pump over a year or two (it pays to shop around).

For the exta flow, put a shunt in the outflow from the pump and direct the extra back into the sump for aeration. I would make the pipe for the drain from the fish tank one size larger than the incoming pump line. There are tables with flow by gravity in different pipe sizes that could give you additional useful information.

In the grow bed use a standpipe surrounded by a media guard. The standpipe will set the level of the water so it overflows into the sump. Make this standpipe removable so you can change the water depth by using a different standpipe if you want. Most people go through the bottom of the grow bed using either a uniseal or a bulkhead fitting to install a standpipe, look for examples.

Sorry if this is too basic, I wasn't sure what you were after.

Cheers

Basic is what I live off of. Thanks for the info.

If I used a standpipe instead of a bell siphon, would the GB never drain completely to allow oxygen to be pulled down?

Why do you want to use one of these tanks?

those tanks are 8 ft tall, what water level do you expect to have in them?

I assume these will be your fish tanks, so you will have a standpipe and a SLO?

check out bright agrotech's video they have similar style tank.

in any case the water level is what will drive your water through the pipes.

say you have 4000L in the tank so for 1 change per hour @ 4000l/hr

if you use 50mm (2") pvc maybe 300mm head

if you use 40mm (1.5") pvc maybe 600mm head

these would depend on size of SLO and the number of pipe fittings

Ahh.. you use both

Could use constant flood, so no siphon required. I assume if the holes in the media guard are only towards the bottom of the guard then you'll get oxygenated water to the bottom.

i read that wrong

Because they're aquaculture tanks that are insulated and all waste goes to the bottom. I also like the idea of having gravity push the water to the GB instead of having a SLO.

I expect to mostly have them full, I'm still finalizing numbers, so that may not be the exact model. But I'm going to need about 1,500 gallons in three FT. But with the legs supports, it'll push it to ten feet tall at least.

Why would I need an SLO when the exit is on the bottom?

Sorry to burst your bubble, but those tanks don't have a steep enough cone to be self-cleaning on their own. The density of fish waste is just slightly more than water so the waste won't settle like you're hoping.

otherwise all the water will drain out of the tank.

you could put the vacuum break on the outside of the tank but it will require a lot more piping and fittings.

The bright agrotech method has an internal stand pipe which has a larger tube over it will so the water exits from base of cone up between 2 tubes and then down the stand pipe and out to the GB.

Can you bury the tanks in the ground? having the water level 2m above GB and maybe 2.5 or 3m above the sump is going to cost a lot of pumping.

it would help if you post a sketch of your planned system.

with a 55deg from horizontal conical bottom I would reckon most of the solids will be easy to push out.

Oh no, didn't know that. Is there an appropriate angle for that?

I actually have seen the agrotech video showing that. I guess it does seem the best way to keep the FT at a safe height.

I haven't thought about burying this type of tank, but it could be a possibility. Would I bury it halfway so the SLO could run horizontal to the GB or would I want a bit of a down angle?

I'll try and draw up a sketch today