Backyard Aquaponics
A place to discuss aquaponics

if you're too worried about zinc poisoning, be mindful that some canned food come in galvanized cans, ie pineapples because they're to acidic to place 'normal' cans. but then again, living in something is more than eating something.

I always wondered why they had that tinny taste??

would you think it would be safe to still keep my tank the way it is are start over? i had spent my buget for what i have .i could change it later, but it my be some time before i could do so.would heavy metal testing help and if found ,could a partial water change help to keep the levels safe. is a swimming pool liner safe to use,because i still have not found a liner that would fit my tank?

Painting the tank would be a good short term fix that would not cost that much, or possibly lining with pond liner. Both can be found at Home Depot Lowes type big box stores.

Pool liner may or may not be safe depends on how old it is and whether it has an antifouling agent built in.

HTH

has anyone had problems with tank liners with catfish putting holes in them. or do i need to change the fish i have.

Interesting, but new to me
any evidence that light or the absence of it makes nitrifying bacteria work worse/better?

frank

There are some test results here:

http://www.int-res.com/articles/meps/57/m057p069.pdf

Those results, and the effect of light on algael growth/slime in very thin layers of media, are reasons for employing "deeper" media filters.... and IMO... thin layers also transfer more heat from the media to the water....

Almost all aquaculture filtration systems are sealed... hence .... no light... and the bacteria seem to work just fine ...

No edit function.... should have said ....

Almost all aquaculture "media based" filtration systems are sealed... hence .... no light... and the bacteria seem to work just fine ...

thanks
although chemics will probably always stay a little like witchcraft to me
I seem to grasp the head lines

wouldn't that mean that the objections to shallow growbeds with coarse media could be overcome by covering them with a black (compostable !) plastic sheet or woven cloth before planting?
would warm up the media during the day too which seems to be good

frank

Suppose so Frank... and that's been done in garden situations....

Wonder both as to the affect on oxygenation and the heat factor though...

Especially when we get days here like we did today.... 36 degrees... and it's not even summer yet...

Could use hydro panda film though... white on one side, black on the other.... and just reverse it according to season.... bit of mucking around though....

36 thats a killer!
it was 19 here

or something similar is what I have thought of doing on the south face of my NFT channels:
paint them black
and when the sun is too hot cover them with white plastic strips

frank

I had very good results with less than 75mm deep media.

Would I do it again? No way - it has no long term 'solids' capacity, it simply becomes too overloaded, and does not allow enough time for the 'solids' to become dissolved.

Regarding the non-lined tin tank, simply drain it, paint with sealer, and go again. I have read about other systems with Gal tanks that have been fine for 6 months, and then the fish start dyeing for no reason. Its usually thought to be the tanks killing the fish. Same thing with cheapy swimming pools.

please explain
did you have enough volume?
frank