Backyard Aquaponics
A place to discuss aquaponics

I have found a submersible pump similar to the one Joel uses. It’s a Lakoni Waterstar 80W 220V 70lt per min at 5.5meter head. Would this pump be adequate for a 5000l system? Of concern is the flow rate.
How do you work out the flow rate for lower heads?

I am planning to use tough flexible hose of the diameter recommended for this pump for both delivery, drain and return. I figured that if the 6mm hole was the bottleneck that a larger drain pipe diameter was not required. Does this sound correct?

For a 1000l system with 2 cubic meters of gravel beds, what would be the expected water requirement to fill the grow beds?

When starting a new system Joel suggested the use of an organic fish based fertilizer. Not being able to purchase such I thought the following might work. A few gardeners have shared with me that you can make a manure tea by suspending a bag of sheep (etc) manure in a drum of water for several weeks. Then diluting and using direct on your garden. I was thinking of hanging a bag of manure in the tank until the plants and bacteria sorted themselves out. Would this work and if so could it be done with the fingerlings?

Sounds like a reasonable pump for the job Matt, many pumps give details about flow at different heads on their box, or in the instructions, or perhaps from a website etc.... I did a quick web search but found nothing on that name of pump..

So far as pipe sizes go, I would try and make the drain pipe larger if possible than all other pipe sizesdelivery and return pipes are under pressure from the pump, the water is forced through the pipe, but drain lines from the beds are only under the pressure of gravity.. I guess it depends on your ultimate design, but you need to be sure that the water flowing out of a bed can always deal with the rate of water filling the bed so that no flooding can happen.

The gravel I use has just under 20% air spaces, hence the water will those air spaces. This would mean that in 2 cubic metres of growbed it would be about 400litres, however, the water is only ever filled to about 30mm (an inch) below the gravel surface of the growbed , so remove about 10% off that. So about 350 litres, about 1/3 of your water when you have a 2:1 grow bed to fish tank ratio.....

I don't know about manure in the tank, maybe compost or worm castings, some of the fishy people here may have more of an idea...

Thanks Joel - I couldnt find the specs on the net either.
FYI - I can get this pump for about 30 USD and a 250Watt version for 25 USD. How does this compare with Oz?

For the 80W 70lt per min I assumed that the run time would be 60% rather than the 30% due to the lesser volume per min when compared 2 your stats.
Does this look correct?

Two 80 watt pumps 160
Pump on time 60%
Power consumption 96
Daily Consumption 2304
Per Year 840960
Cost per kw hr Rp 800
Cost per kw hr per year. IDR 672,768.00 ( app 67 USD)

Thanks Joel - I couldnt find the specs on the net either.
FYI - I can get this pump for about 30 USD and a 250Watt version for 25 USD. How does this compare with Oz?

For the 80W 70lt per min I assumed that the run time would be 60% rather than the 30% due to the lesser volume per min when compared 2 your stats.
Does this look correct?

Two 80 watt pumps 160
Pump on time 60%
Power consumption 96
Daily Consumption 2304
Per Year 840960
Cost per kw hr Rp 800
Cost per kw hr per year. IDR 672,768.00 ( app 67 USD)

hmmmm, that could be close to right.... Very hard to tell when your system will be a little different to mine.... Firstly, in my system there's only any one pump on 30% of the time, not both of them, just one... So that saves you a bit on the calcs, even if you do double it to 1 pump running 60% of the time...

The prices sound very cheap, how come the larger pump is cheaper than the smaller 80W one??

Joel
Because I am a white guy in Indo. The first time I bought the 250w I got charged USD 38.00. The shop keeper takes a look at you and takes a guess how much he can rip you off.
Thing can be quite cheap here especially pumps etc.
Hey this could be a business op - supplying cheap pumps to OZ.

Ahhhh yes..... Don't I know all about the different prices from travelling overseas... What do you think postage would be to get something like that over to Australia? My pumps that I was buying were about $240 I think for memory, so it's possibly not a silly idea....

I would contact the cusoms dept to check out any duty etc. on any items. Factor that into the equation to get a good idea of cost. I bet you still would save heaps!