Backyard Aquaponics
A place to discuss aquaponics

Hi


i am planning to build 2 beds one longest than the other. the longer one would be 400mm deep as well. if i buy EPDM pond liner 0.7 mm thick. One pond liner would be 15m wide and another one 9m wide as these are the standard lengths they come in. what should be the dimensions of the bed if i go with 25 mm insulation. is there any way to figure out the max length of the beds.

thanks in advance

This post is confusing Qutata. You have only given one dimension each for your liners. You have stated that dimension as width, while asking for an answer in length. Also you are asking for insulation to be taken into account without giving any details on your construction methods. Some more information would be helpful.

Unfortunately the pond liner specs are in widths which is confusing me as well.the beds would be made of 50mm thick treated pine and the 25mm insulation will sit in it. Basically insulation will be on all sides of bed.
please let me know what elae i need to provide.

I might be missing something that's not clearly spelt out in your question. But it seems to me that the limit on your growbed length is only going to be set by the space available in your backyard - and other things like the desirable ratio of grow bed wet media volume to stocking rate (search on the forum for more info).

seems to me that you can have growbeds at least 15 m long without having to join any liners. That's very big for a backyard system.

I can't see how the thickness of the insulation makes much difference to your maximum growbed length.

But I might misunderstand!

If you just multiply the depth of your bed by two that will be how much you need to go up on the sides/ends, then add a little more to that for wrapping at the top. Your 400mm bed would need 800mm plus another 150mm for going over the top of the insulation and securing to the lumber on the ends. Metric confuses my math skills even though I know it’s a far superior system, but I think that still leaves 8.05M for length off the narrow roll. As DD said though, your yard and your system will determine if that is the right length for you.

>> One pond liner would be 15m wide and another one 9m wide as these are the standard lengths they come in. what should be the dimensions of the bed if i go with 25 mm insulation.

I presume this is the length of roll in the shop - ie. becomes the width of material when unrolled ?
This is a pretty massive roll. Or is it the length of the material on a 4m/6m wide roll ?

So 9m with 400mm sides would be.

0.4m + 0.4m + some extra (as per Dom above) => say 0.2m for then you have 1m used.
You could make a 8m wide/long bed with the 9m.

you really don't want your grow bed too wide because it gets too hard to reach the plants.


Always nice to have a bit more extra and trim later - words of experience
0.2 would give you 100mm on each side. To be sure I would maybe allow 200mm on each side extra
(so 200mm + 400mm + 400mm + 200mm = 1.2m (1200mm) => 9.0 - 1.2m = 7.8m)

even 300m would be fine 300mm + 400mm + 400mm + 300mm = 1.4m - still 7.6m wide.

very unlikely you would need the 15m wide roll. because it will presumably be longer than 15m.
But if buying by sections cut off the roll then you may be able to save by buying the 15m and the whatever length you need to cover the width of the grow bed.

the pond liners all come in linear meters thats what i have given there. after reading some posts on the forum i realized that 8 m is too long for gravel bed so i want to nreak it down into 2 parts. the only reason i wanted to go with such a big bed is to avoid having a very powerful pump to pump water through the beds as the water looses its pressure due to resistance. i want to go with just a small pump which will pump the floating raft bed on the ground to a gravel bed and a fish tank. si i want to build one long dwc bed and a media bed. in future i plan to have only dwc beds. does anyone have idea about connecting multiple gravel beds without using pump?

>> the only reason i wanted to go with such a big bed is to avoid having a very powerful pump to pump water through the beds as the water looses its pressure due to resistance.

you will have to match a pump size to service the volume of the fish tank (you don't mention that volume).

the beds are less of an issue.
(a) you can discharge water all along the grow bed instead of just one location.
(b) you can run as a timer F&D or as a constant flood and then you can have multiple standpipes.

It wont be an issue for a DWC. With a long bed you will need to provide some air inside the DWC - that is normal.
The plants do not actually need the high circulation turnover - that is mostly for the fish.


as above: "if buying by sections cut off the roll then you may be able to save by buying the 15m and the whatever length you need to cover the width of the grow bed."

You really just have to do the maths on the various cost options.

>> small pump which will pump the floating raft bed on the ground to a gravel bed and a fish tank

Usually you go FishTank to bed (a SLO would work OK) then down to the DWC.
Then DWC back to the fish tank. You usually have to filter water before putting in a DWC else the crap hangs around the plant roots and is not good for them.


are you trying to do something like this ?

yes i am trying to do as above plus a media bed. how long are those beds? any idea?

initially i am planning to use 2 ibcs for fish tank. the SLO from fish tank will go in bio filter which is a 80liter drum filled with media back to dwc bed. the water being pumped from DWC will go into media bed and fish tank. CHOP2

i want to use media beds to have plants like tomatoes plus additional filteration worms etc


please let me know the dimensions of those grow beds and the size of fish tanks of above system if you know

thanks

>> the only reason i wanted to go with such a big bed is to avoid having a very powerful pump to pump water through the beds as the water looses its pressure due to resistance.

You wont need to "push" the water through if you use gravity assist.

So if you're going to use 2000 lt IBC FTs you could use an SLO to drain down (300mm) to the media GB then down again to the DWC (which could be used as a sump, or) then down again into a sump.
If the media bed is waist height you wouldn't want it more than 12-1300 mm wide if you can access it from both sides and 8-900 mm from one side. (Read save your back). If it was lower say 500 mm off the ground it could be wider because you could comfortably support your torso by putting one foot on the surface.

>> yes i am trying to do as above plus a media bed. how long are those beds? any idea?

that system is Joel (Earthbound) BYAP 'commercial' test setup.
It was not reported in a specific thread but it is mentioned around the forum - one thread is this one viewtopic.php?f=1&t=17591 Cannot recall the thread that this pic came from.

I think the width was about 3m, maybe 4m.
I am pretty sure they scooped it out with a bobcat or something similar.
Made a trench and lined it.

If you want a sump return then simply bury a storage at the end and put the pump in it.

Joel might hopefully chip in some information for you.

---------------------------

Andreas thread is also worth a look Crappy Basil growers R Us
viewtopic.php?f=18&t=16235
you need to go to about halfway where he starts building the serious DWC's.


with larger rafts you usually make a lifting frame of some description and lift raft up/out. When remove one then push the rafts along so new plants at FishTank end and older plants at sump end. Seem to recall some threads around here talking about large DWC lifting frames.. Maybe one of Ryan Chatterson (Ryan).

is there any limit on the size of media beds? what would be the best way to connect them say if i have 2 5 meters ling media beds? what pipe size should i use for draining the two beds assuming they are independently draining into one big pipe? Any ideas would be appreciated thanks

>> is there any limit on the size of media beds?

physically no, but nutrients will dictate the number of plants that can be supported.

as long as the water keeps moving - even slowly and you can provide aeration along the DWC then things will grow provided the nutrients are there in sufficient amounts.

>> what would be the best way to connect them say if i have 2 5 meters ling media beds?

if you have a raised media bed then you can just have a standpipe like normal and drop the water down into the DWC as 'overflow'. Pipe diamtere will be dictated by your pumping rate - but nothing more than 50mm would be required. May even get away with 25mm or 32mm if you have multiple outlets.

I would feed at 2 or 3 points into the DWC but you can do that with Pipe T's at the DWC edge.

what size pipe would be good if i want to drain the bed down using siphon into a wicking bed. so water goes from dwc into media bed and is siphoned off from there into a wicking bed and from there goes back to dwc. i want to design wicking bed like below



https://youtu.be/QN8ZxsfnjVU