Backyard Aquaponics
A place to discuss aquaponics

I've done a quick search and not come up with much on this...

I have a project in the planning stage for the school I work at. We are a remote area and while we can get poly tanks here they cost up to three time what you'd pay on the mainland. I was thinking it may be better to use a bobcat or some kind of excavator to dig a pond instead and line it with a heavy duty pond liner. After a quick google it seems I can get quite wide dam liner around 8m (can you join it???).(http://www.hydroponics.webcentral.com.a ... dliner.htm), or even 15m (http://www.rockaroundtheblock.com.au/ca ... 35&c=20426).

So I am after some pros and cons of using both a soft liner and a rigid poly tank (apart from the pond liner can get holes in it con).

Security is an issue for two reasons. The most important of these is child safety. We are a central school and have students from kindergarten to yr 12 at the same school. I don't want to risk a drowning. With a liner I was going to sink a few concrete pillars around the perimeter and secure a piece of weld-mesh to it to cover the whole pond with a paddlocked 'lid'. I don't want to risk relying on a gated fence (though this will still be included in the submission) as the 'Norfolk way' does not place much importance on closing or locking gates or fencing things (I don't even take my keys out of my car most times!)! The second issue is one of the locals helping themselves to the fish as we raise them . The weld mesh will help reduce that risk - maybe. The high sided poly tank seems to be better in terms of safety as little kids are less likey to be able to climb in though I'd still need to cover it with weld-mesh. I don't want an overly complicated system either. My vision for the school was one fish pond with a number of grow beds situated around the edge - not a whole lot of little tanks and little beds etc.

Any thoughts or experiences would be greatly appreciated.

Having used liners on a couple of ponds, it is ALOT cheaper to do then tanks, however its ALOT more work!!!! But then i was digging through clay and rock by hand.......whereas a bobcat or an excavator would lessen the time and effort needed to make it........


If it is going to be big, i would definately go with a pond and liner

OzV-liners can be repaired and glued/joined. Similar to bike tube repairs.
I used a pond liner and concreted it using gravel as the aggregate, mainly this was to secure the liner into place.
The most difficult part of a ground height pond is access and as such I created sides to 'lift' the working area to about 600mm above ground.
There are a few photos kicking around.
C1

Why was access difficult with a ground level pond? I have about 10 long handled (6ft) wide mouth nets in my supply room that might help with this...hmmmm

that'll fix it!

C1, with your liner did you cover the whole bottom and sides with gravel?

no! I used conc to secure the edges with rocks and slate, that was once the water filled out the shape.
There was a 30 years warranty with the liner figured it was worthless so threw it in the bin.
I used as a protective barrier carpet that my mum had graciously given to us to use.
C1

hi guys
had a look at the hawain model of joining five plywood sheets end to end to make a 3.5m dia tank 1200 deep. The 6mm marine ply i priced was 28.00 per sheet so about $150.00aus. However when i went to clark rubber to price the liner they quoted me $780.00 dollars so with sand for the bottom and some girth straps that would take the total to approx the $1000.00 mark. How does this compare with metal and poly as i havent priced them yet. I can also source a 40mm out submersible chineese made pump for 150.00 which i thought was pretty cheap.
pete

From what I have priced up for Fibreglass aquaculture tanks, around the $1600 mark would be about right for a 12,500L tank. Don't forget to calculate labour and wonderful time you will spend building it *cough*.

Will you bury this tank in the ground for support? I would hate to imagine if somehow the ply came apart.... whoooosh!!

the one in hawiai is above ground on a sand base with it looks like three girthe straps. But with the water crisis poly and gf tanks are skyrocketing in price.
My other option is a disused inground septic tank of approx 1000lts it is 1200d x 1888h i thought that it could be cleaned and it would keep cool in the summer heat of ctrl qld.
pete

bf, did you pm C1

Don't you just love those cryptic messages