Backyard Aquaponics
A place to discuss aquaponics

thanks guys for your input. But i thought the ideal ratio was 2.1 I was trying to achieve that?. Is the problem too many growbeds based on a 2500ltr stocking density and not enough sump capasity? The fish tanks holds about 3000ltrs, or is it the need for 2 pumps one in the fish tanks and one in the sump? joel your system with 4 grow beds is based on a small sump. what am i missing here? Should I cut back on the grow beds? Sorry i am a little confused here. Vb i will call you.

AP

Yeah, you a holden man or a ford?

ok, now that brings me to the only real issue that I have with the auto siphons in general.... the water that is left in the beds... I'm not even sure that it is an isue, but your always left with a fair level of water in the bed, but with a standpipe, the water almost always drains right out.. Though in this situation it is probably an advantage in a way, because it is less volume of water moving around and being pumped from the sump...

Yep - the remaining water has caused no issues for me - it is basically constantly replenished anyway so DO stays high. Give me a call AP - much easier to discuss the whole thing like that. Can answer your questions (and follow-ups) really easilly and also help you to decide what is best for you.

EB in your appinion in a flood and drain is it better to fully drain or leave water in a 300 mm growbed if leaving how much xx

Joel - Ford at the moment .

To answer your questions for the benefit of the group AP - Joels current large system is a 2 pump system with the pump in the small sump turning on as it needs to to pump the water that leaves the beds back into the tank. In this type of system all the water loss is seen in the main fish tank. In my type of system the water in the fish tank is constant - with all variation being seen in the sump. If you were to use Joel's type of system with exactly the equipment you are speaking of - your 3000 litre tank would drop to 1000 litres when the beds are flooded with 2000 litres. Unhappy fishies I'm sure.

I'd test those flooding figures if I was you though - you might find the gravel displacement is higher and once the flooding level is also taken into consideration the water usage may be quite a bit less than you have calculated (who knows).

I must try a side by side experiment in one of the new systems I'm going to build.... Although..... No, it's not so easy to do it in the same system, it's either intermittant flow and standpipes, or continuous pumping and syphons......

It is also possible to do intermitent flow and autosiphons by drilling a hole at the bottom of the inner siphon pipe which will allow the bed to drain if the pump turns off. I plant to do this to allow me to have the pump turn off at night in winter (wouldn't want the bed to stay at the level it happenned to be when the pump cut out).

Looks like this is the place to be tonight

I'm toyota..... trick question..... but have had more fords...

Ah, but I don't see the stand pipes working in the same way for this system we are discussing.... It would be like my small second system.... Pump in sump on timer, pumping into fish tank that has constand level, flowing out into growbeds that have standpipes... Pump switches off, beds slowly drain into sump before pump switches on again...

I wonder, on a multibed system like this, with 8 beds would there be any issues with flow rates into the 8 beds to make the syphons start and stop ok?

I guess the simple thing is that the way the design is shaping up, it would be extremely easy to go one way or the other... The only difference is either having standpipes and a timer, or autosiphons and continuous pump.. everything else in the system remains unchanged... Infact it would only take 5 minutes to change the whole system from one way to the other, rip out siphons, put in standpipes....

I agree.



I don't think so - just need to make sure that the pump/s pumping water from sump to fish tank have a collective pumping rate high enough. I pump less than 1500 litres an hour at the moment with my one bed (and that is before the pipes start filling with biofilm. An 8000 litre per hour pump or a couple of 4,000 litre per hour pumps (running continuously) would do the job fine. Would turn the system water (tank and sump) over more than once per hour. The only reason my current little pump has such a low flow rate is that it is going through a venturi which takes a lot of the oomph out of it and the head height is not ideal either. At the moment this suits because if it was any higher I'd have to crank it back otherwise the siphon would not stop (my autosiphon is 25mm inside 50mm - so flow rate is not massive, though is ideal I feel).

BTW Joel - we have a Ford and a Toyota

now in my stand pipe system I have an 9000l/h pump, but it only runs for 10-15 minutes an hour.... 1/4 running costs.... but then possibly not as great filtering and/or load capacity because it doen't turn the volume over as quickly.... Dunno.... I certainly get good pretty stocking densities though...

we have a madza, am I still okay to be here LOL

Great discussion VB..... Though I'm gunna have to go and watch the bill soon...

I don't know Stu..... Then we'd have to let the Lada Niva drivers in as well...

I got the dvd and red the book flood and drain works well for me