Galvanized mesh in pond - long term issues?

[TekWarren]

I have been using quilt batting inside a folded piece of wire mesh...I believe it is galvanized, the stuff I used for rabbit cages as a kid (4H). Anyway, it has pretty much become a permanent pre-filter for my skimmer, I pull it out and rinse every day, or every other day and it is keeping the water very clear. I was wondering about coming up with something a little neater using the same mesh that would also serve as a way to keep small floating plants from being sucked into the skimmer... Even if I don't do that I will continue to use my current "drop in" pre-filter. Are there any issues with the galvanized mesh and long term contact with the water? By long term, I mean the few months of summer we have in Michigan. I would not leave it in during the winter.

The small floating plants won't be small all summer, but as my water lettuce and hyacinth fill up the baskets they sit in on top of the biofalls I snip the offshoots and toss them into the pond. The lily pads hold some of them in place pretty well but occasionally as the floaters move around I will find one in the skimmer box leaf net. I know floating rings are an option for the plants also.

 

[HTH]

Good luck finding an easy answer to this. On one hand you find people who have kept fish in galvanized stock tanks for years without problem and there are a lot of places saying it is bad.

My thinking is that zinc is used as a trace element for plants. I don't know that fish could take it directly from the water but may get it from algae and other plants that take it up.

The safe answer is not to use it.

I use old plastic photographic trays with holes drilled in them to hold my quilt batting. It seems to work a bit better for me if I keep the batting of the tray bottom with eggcate light diffusion plastic grid.

 

[TekWarren]

Hrm, I guess in a perfect world there are no safe items derived from chemicals that are safe to put in a pond...even some plastics I would I think. The batting does such a great job keeping the water clear and in my case is very accessible for a daily rinse. I want to keep using it but will look into other ways to hold in place. I saw a video some time ago of someone who set it up with a similar mesh but the waterfall water fell through it, maybe better than soaking all day but not sure I can do that in my setup and make it look decent. For the time being I will pull it out (fairly small square piece of mesh) and put it back in as needed until I can come up with something better. The batting is clogged pretty good within a day though so having in place permanently right now keeps the water clear but not worth risking the pond life.

 

[TekWarren]

So I found a milk crate in my storage shed, tossed the junk that was in it, washed it thoroughly and came up with this skimmer pre-filter:

http://www.flickr.com/photos/95980543@N05/9162522214/

The milk crate sits about perfectly in front of the skimmer opening...but does not completely block it off. A piece of quilt batting is held in place by the current so the finer algae and stuff should still get caught. Additionally, for looks and maybe some bio filtration I threw in some hyacinth and water lettuce trimmings. The crate should keep other floating plants from being sucked in all the way as well act as a sort of pre-filter. Probably reinventing someone else's wheel here but I was pretty impressed with myself LOL. So now I have plant filtration at both ends of the water circulation system and can maintain my fines filter.

I'm assuming the plastic crate is safer than the galvanized mesh and it definitely looks better...well, aside from being bright red