Backyard Aquaponics
A place to discuss aquaponics

Hi everyone,
Desperate for some help. I suspect my gal tank is leaking zinc which is killing my trout. it has a polymer lining, but i suspect that there is a leak somewhere. Some questions please?

1. How can I test for zinc?
2. If I move my remaining fish to an IBC tank, is there any point, or are the fish going to die from existing condition anyway?
3. My grow beds are also galvanised tanks (lined). I assume I'll need to change those as well??
Thanks very much for any assistance,
Todd

Any chance of a photo of your set up Todd? Also at this time of year water temps are a likely cause of trout deaths. Not sure how to test for zinc other than water analysis at a laboratory. Where do you live?

1.You can get test kits for zinc, like these: http://www.watercenter.com/product_line ... Kits&Cart=

2. I would move some to the IBC and see if it makes any difference.

3. If the tank/growbed is lined you wont have a problem with zinc toxicity. If the liner is damaged then yes it could be the cause of the fish losses. One thing I can tell you is that trout wont even last 24hrs in a zinc tank that is not lined though this may be dependent on the PH to some extent.

Hey Faye, he's from Sth Tassie so I recon he could do Trout year round no probs.

I don't think it will be zinc Todd. I have systems using the same lined tanks and growbeds and have not had any problems. My water even overflows down the side of one growbed into the fish tank below 24/7 running over the straight galvanized surface.

Hi - and thanks for the responses..
I've attached a couple of photos.. please excuse the mess.

If you see the inside photo - the tank lining has this strange orange stuff coming from it, and also a black. The black is like a mould, and very hard to get rid off. It seems to be at the one point of the tank, where the join is.

Just some responses to your messages - As Troutman said, Im in southern tasmania - and high on a hill, so heat isnt an issue.
(Earthbound.. are you running trout?)

Troutman - I will take your advice.. and try some in an IBC.

Welcome what your thoughts are on the problem if the phtos give you any ideas??

thanks again,
todd

In the last photo is that an indication of Rust...? if so it looks like the liner has been damaged in some way..

are their any indications of rust on the outside of the tank..

Also where the wires join both sides of the tank how does the area around them Look..

Juergen

Yeah, looks like a failure to me... how old is the tank??

Tank was bought christmas last year - so coming up to 12 months. there are no indications of rust on the outside of the tank, - where the poles go across, there is also the black stuff.

So - there is no sign of this (either the yellow or the black) in the GB's. The height of the GB's wouldnt require the join.. That being said, I cant say what is going on at the bottom of the tank under the gravel.. Im wondering whether I should scrap the lot and start again. We can use the tanks as regular garden beds.. not sure what to do with the 6000 litre tank..

Wonder if there a test I can do that checks if the orange stuff is rust? I think I need to do a water sample test of metals etc at a lab..maybe?

If the aquaplate lining is faulty... then raise the issue and ask for a replacement under warranty...

I wouldn't worry about it necessarily, though I can;t see fine details, but I have seen tanks do that in the past, especially where the silicon is, algae type growth growing in splotches where the silicon is especially.. Does it seem to be concentrated where the silicon is and at the water surface mainly?

With the tank being buried, how much of the tank is buried..

Juergen

about half..

how wet is your soil..

Juergen

Pretty dry Juergen - the whole setup is in a hothouse

I think that you might have issues with try a Warranty job on the tank due to it being buried..

I'm pretty sure that there is a clause in the Warranty conditions that says the Warranty is void if the tank is Buried.. even to about 30cm's..


Side issue.. What has the temperature been like in the hothouse..?? Could the water temp be to hot for the Trout.. Maybe a method to cool the water..

Are you running constant pump flow or timed flow..?

Juergen