Stainless Steel & Floaters

>Couple questions: One, I put some bog and floating plants in a stainless
>steel barrel outside in the backyard with a powerhead for circulation. I've
>added Chelated Iron and trace elements...but...<snip>

> When you lawn turns yellow, the recommendation is to add nitrogen
> rich fertilizer. Similarly, aquatic plants can't live on trace
> elements alone! They also need the macro nutrients- N, P, K, S, Ca,
> etc. Unless you are feeding fishes in this container (to provide N
> and other nutrients), you should be looking at a more complete
> fertilizer.

Well, I figured with water changes, lots of biological activity in the
barrel, decaying leaves, bugs and such, that the Macro elements wouldn't be
the problem, but it's simple enough to add some general purpose pond
fertilizer or something. The barrel's probably not large enough to support
anything but a guppy or betta maybe, but I haven't added one and won't be
feeding the nutrients in. I'm not looking to create the fine nutrient balance
in the barrel that I have in my plant tank. I was mainly concerned the
stainless steel barrel itself might be the problem somehow.

Thanks for the advice,

Kent Elliston, Sacramento