Backyard Aquaponics
A place to discuss aquaponics

Orderred my 1st rainwater tank today from the Ekka. 22,500 litres, will be about 6 weeks before I get it. That plus some rain will put an end to me having to use neutraliser when doing water changes and also will mean that I can water my dirt veg gardens again .

Did some work on my grow-bed stand today. Didn't have much time to spend on it, so it is still not finished (have to put the legs on).

In planning my big system in my mind, I have always been keen to avoid having to have a 2 pump system. I wanted to be able to rely on gravity feed back to the fish tank - therefore only needing to pump from fish tank to the grow-beds. I have come to realise when deciding how long to cut the legs that my grow beds are going to be pretty friggin high if I am to gravity feed back to a meter high tank (clearly this is why Joel ended up with the sump).

Now I have a few option available to me here:

1. Make grow bed stands high. Eventhough the top of the bed would be approx 140cm high to achieve the gravity feed from the drain back to the fish tank, maintaining a bed at this height would be okay for me (I am not really tall, but at 6 foot am not short either). If growing taller plants, height of greenhouse and harvesting (for example tomatoes) could present some problems). For things like lettuce there are no worries.

2. Make grow-beds shorter but dig fish tank partially into the ground so that I can still gravity feed back to fish tank. This may be a reasonable option for me - provided I don not hit big rocks where I am planning to put the system. All the same it provides significant extra effort and means that the system is pretty much going to stay in that position whether I like it or not.

3. Settle for a 2 pump system.

Which option do you all think I should go for?

One positive is that in the interim I will be able to gravity feed even with a lower grow bed stand, because the ponds in my test system are no higher than 50 or so centimeters.

Hi VB, I have it in my mind to build a big system patterned on Joel's with 2 x pumps etc, but I am thinking I will knock up a med size system in the next week based on a one pump system with a smaller tank, one of those 600 ltr ones I have, sitting on the ground and a grow bed on longer legs. I understand what you mean by the grow bed being a bit high. Don't want to have to use a step ladder to pick the tom's !!!
There are just too many possibilities !!!!!
Mojo

I am doing the two pump system as in the book, beacuase it is tried and tested, and although it involves more bits that can break, I want my groww beds at a nice height for planting and harvesting.

Steve - the 22,500 litre tank is my rainwater tank. My fish tank will be a hell of a lot smaller than that. Provided I work out tht it will hold enough water for a flood and drain design I will probably go for one of Murray's 2000 litre jobs. If it doesn't I don't know what I will do, poly I guess. Would love to connect 2 of Murray's together to increase the size o fthe body of water, but my wife would have my nuts for spenmding that much money (she will probably have my nuts if I buy 1 - so maybe I should just buy 2, same result ).

Murray - a medium sized system with one of your 600l systems is a good idea. Will still make your Jade's happy and will show potential purchasers that you are happy to and have used the product. I was considerring using a step ladder to harvest the higher fruit - but greenhouse height may become a limiting factor .

Monya - This is my issue also. I figure that by using the 2 pumps I am doubling my chance of a failure, doubling the cost of pumps (which are not cheap) both initially and replacements and also I have some concerns about the wear on the pump in the sump as it is continually switching on and off. If I go this system I think I will try and make sure that the sump pump has enough capacity to have to pump out only once or twice a cycle (though this does mean that the fish tank will be lower for longer ). Ideally I would like a continuous running pump going to the beds, which is why I am interested in all the discussion on sysphons. Ahhhh it's getting difficult now, I'm going to have to make some decisions soon.

Cool VB, sink it 50% to 100%. My 1000 LT tank is 80% sunk.

LOL when i read 22,000 i thought "thiis blokes got the bug BAD " LOL

One step closer to getting my little test system fully operational. Have welded the legs onto the grow-bed stand. I ended up putting 70cm legs on (using 50 x 50 x 5 angle - copied your example there murray, though I have welded legs directly to the top). I still have some more welding to do before it is complete. I have pretty much only tac welded the legs on at the moment and I also want to put a diagonal cross bar on to stabilise it all (similar to the ones Murray has on his website). I had a few problems with the welding. My welder is a Cigweld Compact Turbo. Max amps is 130. I used my usual 2.5mm satincraft rods. Problem was that I had difficulty getting any penetration. Had to crank it right up, which meant that I could only weld for a few seconds in each cycle. This is a huge pain in the arse and makes me wish that I had a much more powerful welder. Funny thig is I had not difficult welding the top using same steel. There are differences in the nature of the weld, but other factors I think are the size of what I am now welding legs onto (hard to get sufficient heat into the bed top) and also that the day was fairly cold. In hindsight, I probably would have been better off doing something similar to Murray (ie having the legs joined to a horizontal piece of angle and then bolting this to the stand top - I might do this next time). When I do the rest of the welding on the legs to finish the job I will try for a hotter day and make sure the metal is pretty hot from sitting in the sun (which I was a bit today, but not as much as it could be). Does anybody have any other suggestions as to how I might be able to improve the weld performance. Anyway - here are a couple of pics:

Fits nicely VB

Real snug - in fact if anything I am worried that there is no room for movement. I'm not sure what will happen if there is major contraction in the cold. I think it will be fine.

Should be ok, looks like there is 5mm or so around the edges?

do you find that its a bit wobly with no braces on the legs? I made almost an exact copy for the bath tub ages ago, it needed (still does ) a brace between the legs, i think

Steve - in some parts there is 0mm gap. Will definitely need bracing to be safe.

Good one VB, Lookin good....

Perhaps I could sell them as kids beds, Didn't think of that !!!

As sales increase on my Grow Beds you will be glad I am sure to take every Wed off work to come over here and weld up stands for me ??? no/yes ?? Gooda pay for you mate !!!!

Marios

Mate - you haven't seen my welding, though I am sure it would be better using your MIG. I am starting to realise that the little ARC welders have significant limitations (well I guess I always knew that - but didn't think it would affect me).

Thought it was about time I put up a few more pics of my fish. Have only taken pics of the ones in the aquarium as the ones in the pond are too hard to photograph.

Some more.