Backyard Aquaponics
A place to discuss aquaponics

G'day everybody,

just a quick questions about Yabbies,
I am thinking of making a raised timber FT which is lined with black plastic/ pond lining (I would try and find the thickest available).
I would ideally like to have both fish and Yabbies in the FT, but after reading up a bit on the yabbies.
I have found out that they are big burrowers, my main question is.

would the yabbies burrow through the plastic and ruin the FT?

or

if I were to add heaps of Hides (i.e PVC pipe cut offs, rocks etc etc), would the ample protection stop the yabbies from attempting to burrow?

I have looked over the forums and have found this question asked before but didn't really find the answer I wanted.

Cheers in advance

Damian

Hi Damian , we have our ponds at work lined with dam plastic and the Yabbies dont damage it , we only have dirt in the breeding pond as they seem to breed better in natural burrows , our grow out ponds have bundles of pvc pipes with end caps on 1 end and they seem happy enough , hope this helps . oh and we have small holes drilled the length of the pipe so they sink , and drain at harvest , cheers

IN a tank you will inevitably have folds in the plastic unless you have taken care to form-fit your liner (Like a swimming pool liner).

I am assuming "yabbies'" is generic to include all species of crays... I had redclaw.

Yabbies eat algae.
Algae grows on the liner.
Liner gets eaten where the buggers can get their mouthparts on.
They WILL eat through the liner.

I would not use a lined tank for yabbies' again unless the liner was form fitted.

Thanks for the response!

I have still been searching all over the net for more info,
on one site it did say that where the liner folds it is more likely to wear out due to the yabbies eating all the waste that accumulates there.

it went onto say that if all the folds were covered (either hot sealed or layered) that the yabbies were far more unlikely to ruin the liner. (providing they have enough hides)

the description of hot sealed seemed to remind me somewhat of a laminator, where the pieces were heat sealed together until they fitted the required shape. I assume this is the same as being form fitted Poppa?

now I have no idea how to do this and I am guessing this would cost a few more pennies than I want to spend, so I am leaning more towards the second option. which requires one or two complete liners for a base, and where the liner is folded, another liner is laid over it and either glued or taped to make the liner fold less.

So this leads me to another question, is there a type of glue that is unlikely to harm the fish and unlikely to break down in the tank over time?

Cheers again

Damo, yabbies are a great addition to AP in small numbers but I wouldn't invest too heavily in backyard yabbie production as you'll be slightly disappointed Im sorry, the returns will be minimal depending on your intended FT size.

Yabbies are omnivorous so most things go but plastic is definitely not on the menu. But having said that Ive heard of them clawing through pump power cords but Ive never witnessed with any of mine over the years so Im on the fence on that one.

Could they claw through a liner? I find it doubtful but I agree they could pierce a fold.

How big are you intending the FT to be?

I'm looking at introducing some redclaw into my set-up, but am using a sump tank made by two IBC's welded together with a capacity of about 1500 litres. Is there any chance you could use an IBC which will be much stronger?

G'day Charlie,

The main idea of the yabbies would mainly be to help the system run smoother, and if any get to a decent size to be served with the odd bit of garlic butter!!

As for the FT size I am still "negotiating" that with the Mrs, but ideally I am looking at maybe 3M x 1M x 1M. I am hoping to try and stock rainbow trout, which I have heard are less aggressive towards yabbies than other species.

As I said earlier I have to make this as easy on the eye as possible otherwise the better half won't be happy!!

Cheers for the responses guys.

I can only tell you from experience. Not a nice thing to see leaks on a 1500 gallon tank, Granted the lining was thin, only 6 mil poly (greenhouse covering.) My two tanks 1500 gallons each cost me $50 to make and I would not hesitate to build them again except not with crayfish (unless caged). Because it was made from a single sheet of plastic, the bottom was smooth but the sides were a series of fanfolds that left a ton of places for the water devils to cling to and chew on. after I drained the tank, there were dozens of spots that were a molecule away from springing a leak, or that should have leaked except the folds tended to self seal. This was in one season.

I also had them eat through a wire to a remote temperature sensor (about the thickness of ear phone wire) in an aquarium (and I watched them do it!) so they have no qualms about chewing on plastic if it's covered in food.

My next self built tank will likely be 20 mil epdm, with a single layer round the side and a layer on the bottom with some type of glued seam where bottem meets wall... Stickfins (Florida redclaw grower) used mini walmart swimming pools with the normal vinyl liners with no issues.

If anyone knows of a tool that can heat join two epdm sheets I'd like to know about it.

Cheers Poppa,

i will have a look round on the net to see if there is anything available for joining two sheets together.
i would definately go for at least a 20mil lining and maybe do 2-3 layers just to be sure.

our Yabby ponds are lined with 22mill thick plastic cut and welded to fit , no folds , and the welder is 17k a bit much for the home handy man lol , if you really want red claw i would dedicate an ibc to them , they shouldn't eat that in a hurry

I pretty much have decided that in order to raise redclaw in aquaponics I would resort to a cage system. 3 layers of 20 mil = $$$. Think that's over ill as well.

So Buddah, what species are you growing? Sounds like you're commercial? Just wondering if you're using any of the newer hybrids. I stopped following the research the past few years as it was too frustrating reading about all the new advances and me without a place to grow 'em. Hoping to rebuild this year if I get off my duff and get her done.

Hey guys cheers for the ideas,

Bhudda, the ibc would make the whole thing alot easier, unfortunately the mrs took one look at them and said "NO". (ugly, big etc etc)

so that was the end of that!!

Poppa i have found a place not to far from me that does the liner for $6.50 a msq, so its not gonna hurt the pocket too much. i also plan on recycling majority of the timber. So hopefully the main build won't dig into the beer fund!!

cheers!!

Poppa , we just have the good old fashioned Cherax destructor , or blue yabbie have not tried the hybrids dont think we will , prices are good for what we have , if it aint broke dont fix it

Dammo , you can clad an ibc or get a more understanding wife glad mine isnt reading this lol

Hahaha
Bhudda if i just got a new mrs i dunno if i would have the pennies for the ibc lol