Backyard Aquaponics
A place to discuss aquaponics

Close AP... That is more the way I was recommending, except instead of using the float switch to turn the pump on and off I would use a $10 timer.. In VB's suggestion the idea is that the pump runs continuously, pumping from the sump into the fish tank, overflowing the fish tank into the growbeds.. The growbeds then all have an auto siphon, so as each bed fills it starts it's siphon and drains out into the drain tank. The inflow from the fish tank is less than the outflow through the siphon so the bed drains.. So the pump never turns off in this style of running, the flooding and draining of beds happens because of the rapid draining of the syphon..

To change this style VB was talking about, to the style I was talking about, with the standpipes, you would just take out the siphons, put in stand pipes, and plug the the pump into a timer..

Interesting idea for cycling two sets of growbeds MF.....

So EB you would just time how long it takes to empty 2000lts in to the fish tanks/growbeds? How many times a day would you think i should need to cycle this system? Explain to me more about the how the timer works?

AP

timers just plug into the wall and then your pump plugs into the timer, you can get them from B for under $20 i think.

i like the HPM brand the best. most have a on/off sequence every 15 minutes, so the shortest you can run the pump for is 15min and then up in 15minincrements.

Yep, I have it just as Steve said, I run the pump for 15 minutes, then leave it off for 45 minutes, then on for 15 again off for 45 etc etc... 24hours a day... The beds drain out over the 45 minutes before the pump switches on again to fill them back up..

EB and Steve I understand the principle, but what volume of water will be pumped in 15 minutes? or does that depend on the litres per hour of the pump? For example my sytem will need to flood 2000lts in 15 min?

AP

Guess that means ya gunna need a 8000ltr/hr pump AP... LOL

EB, just posted the new Ebara pumps which would do the job... have a look
Good volume delivery, great head range and handle solids....

You don't have to worry about head height as such, but factor in the total length/size of your piping to deliver to all beds....

Yep, thats dead right AP...... My little "2nd system" has the 15/45min cycle and it's only got a 20W pump. Pump is roughly sized to the system, a little more flow is ok because it will go over the standpipe and down the drain..

Thanks.... however, I don't think you guys understand that it is the only way

With the volume he has to move, AP either has to go with a mondo pump (which still doesn't solve the volume deficiency issue) or continuously pump running a higher volume of water in his system than what his sump can hold risking pump failure and flood. He has very little buffer between sump capacity and grow bed capacity if all fed at once (which is the only possibility without a gate valve). This means that (when running on a float switch) just a small amount of water evaporation will shut down the system.

I'm not saying this to be argumentative. If he had a larger sump or reduced his grow bed capacity the problem would be solved.

Timers work better than float switches IMHO...and can be had cheaply.

Yes I guess with this method that it is the only method MF...... With pump in fish tank it's easy to do with a second pump, but not so in this situation...

Yep, definately timer control if going for standpipe method. There wouldn;t be such an issue with water volume in the system, if a couple of the beds are used as floating rafts kept full at all times.. Then with flood depths in the other beds kept to a minimum I don't think it will be too bad on water top ups...

Rup, I did notice the coincidence on the pump sizing, but I wasn't going to comment.... You edited your post.....

Not the only way at all - could have the beds at 2 levels with one set feeding into the next (as I suggested earlier). I do like that valve though MF.

Come on VB...... You have to build your system, I want to see it..... The pump in sump, autosiphon, tiered, staggered, growbed....

Cmon mate - I'm spending way too much time on here to actually build a system - jeez

YOu have a couple of hours to go before bedtime VB, start diggin'!

and welding, and gravel washing and greenhouse buying and money saving

its the saving part that really stall us aint it VB