Algae on old plant leaves and decorations

The beneficial bacteria grows on surfaces, not in your water.

It doesn't sound like your tank is cycled.

I think (as already mentioned) that the algae is just taking advantage of your lack of adequate nitrogen availability, which I would probably attribute to the nitra-sorb.

At the same time the nitra-sorb is the only thing that's really keeping inadequate water from turning into terrible water for your fish.

If it was me I would try to find some used filter media from an established tank that you could use to seed your own filters, and stop using the nitra-sorb when you do, and then see if things stabilize themselves.

Otherwise I would try to find someone who can house most/all of your fish for you while you go back and cycle your tank, preferably fishless, or with some hardy fish, and then reintroduce your stock once you're done.

You can use algaecide, and it will probably kill your algae... But you still haven't corrected the reason that the algae is there in the first place, so it will just grow back. On the other hand, correcting the cause of the algae will cause it to go away on its own.

Otherwise a little bit of algae can be normal.