Backyard Aquaponics
A place to discuss aquaponics

Ok. So the treated pine bearers hubby bought to carry the cladding for our AP system have been treated with CCA. (Copper, Chromium Arsenate)

So have the treated pine palings I was planning to use to clad the system.

If I use heat treated pallet wood in all the areas where there's a risk of water run off entering the STs I should be alright shouldn't I?

I have painted the CCA pine bearers as they get closer to the hatch in the ST. (As shown in photo)

The capping on the system will be ACQ wood.

Thoughts?

my 2 bobs worth
several coats of paint on the treated timber, if that stuff gets into fish tank its bye bye fishys.

The run off will be minimal if you use the heat treated timber in risk areas above the fish tank so I wouldn't be too concerned.

Ok - will do. I've already given it all one coat already. The hatch to the sump tanks is pretty small. About 30cm by 60cm on the far right of the STs in the photo above. (STs are beneath the grow beds and wrapped in black shade cloth - you can see all the grow beds and the STs in the photo below which was taken before I installed the treated pine bearers. FTs are in the shed to the right of the system.)



This photo shows how small the access hatch for the STs is. (Photo taken when I first cut the flap)



In addition to keeping the flap of plastic there I have also made a cover out of untreated wood (visible in the first photo I posted, and mainly to stop kids messing with the STs) which should act as an additional barrier to rainwater run off.

I've noticed that before I connected the GB plumbing to the STs the water level in the STs stayed pretty constant even when we had a lot of rain - so I think the rainwater run off that gets in there is minimal.

wow! beautiful system and coming along nicely

Tonzz, I'm sorry but that is incorrect information, and an extreme over reaction. CCA does not kill on contact. Termite say oh shit, that doesn't taste nice and leave it alone. Copper stops it rotting.

SydneyChick your set up is looking good.

CCA is all good to use around the tanks, but I would not submerge any in the beds or tanks due to the risk of leaching of heavy metals from the wood.

Heat treated pallet wood will rot if exposed to continuous dampness. The heat treatment only acts as a method of killing critters that might be alive in the wood at the time of heating and does nothing to improve the durability of the timber. The theory being, that the pallets are made straight after heat treatment and will be exported immediately, so no nasty critters will get exported in the wood. The reality is if the pallets are lying around after construction, critters can still call the pallet home.

Thanks Dr Bee. Those are some good tips! I really appreciate all the advice I've received so far and I will definitely be playing it as safe as possible.

I'm painting the pallet wood as well. All wood I'm using is getting a few coats of a "rainwater collection-safe" paint. Obviously the CCA wood will receive an extra cost or two since I want to make sure I'm not poisoning my fish/family.

None of the wood will be submerged in water, and I'm also nailing the cladding so that it is a few cm off the ground so none of the wood will be sitting on wet soil.

Eventually I won't have to worry about it so much as the whole system will be covered by a hoop house which will in turn be covered with greenhouse plastic sheeting. Once that is done the whole outdoor part of the system will be shielded from the rain.

I live in one of the wettest areas in Sydney unfortunately and sometimes we just get weeks and weeks of relentless rain.

Thanks SC,

Hope you avoided to much damage from the storms today.

No damage here thank goodness. Just soggy ground and water everywhere. The ducks are loving it!

Treated pine works well i use the edging pine at $1.20 per metre for 100x16 , it screws easily to ibc frames and once it has aged can be blasted with a pressure cleaner to remove the grey and sealed with a water based decking sealer

Thanks Rossco! Your system looks awesome.

I am enjoying how easy the pine palings are to work with - however the sanding and painting with two coats is very slow!

Are you going to run the palings full length to the ground?
Only curious in regards to plumbing access if you decide in future to add extra beds or dwc bucket to the return line underneath, i would consider one or two removable access panels at either end of where connections are.

Thanks Rosco! I am indeed planning two hinged access panels on the left of the photo so I can access the plumbing under the growbeds. This will be useful for many reasons from maintenance and leaks to the seemingly inevitable expansion!

I will probably nail the palings in place and then cut them so that the finished look is as seamless as possible.

Sorry if I missed it but have you done a test run with media in the GB's to check on the support stability etc, there can be a bit of weight when Gbs are full. In some cases the plumbing can move a little with added weight too.

A better photo of the cladding-in-progress:



That salmon colored board peeking out behind the cladding is Knauff Extruded Polystyrene panels I've put in place to insulate the STs.

A photo of the insulation which is held in place by the cladding: