No, I do it totally different and this year I did it different then I ever have before. In the past I jsut used sponge filters/powerheads. Since I was doing a low volume of fish (like 6-10 minnows) per 75g or so tub , I just added water, added fish, added plants and that was it. I do not use substrate, and I don't do water changes (unless we have a dry spell and the levels dip).
With this setup, I am not using any conventional filtration at all. I have teh top bin set up as a sort of veggie filter (as I add more and more plants). The water from teh top tub overflows into both bottom tubs. Each of the bottom tubs has a 285gph pump which returns the water to the top tub (they are also tied together with 1.5" bulkheads to help with leveling of hte water and also have overflows at teh top in case of rain storms). The provides more than adequate aeration and the turnover rate is pretty decent (570ghp for about 200g of water) so I don't really worry about the filtration aspect. We also get a fair amoutn of rain here from spring all the way through fall, so evaporation and "water changes" are done for me. Thi smay change with the addition of goldfish, but we will see.
This year, I won't have fish at all in teh top bin, only fast growing marginal, shallow, and floating plants. The bottom "left" bin will raise meteor minnows and the bottom right will have 5 juvenile goldfish (only a couple inches).
I do add large river rocks and chunks of bogwood to anchor plants too, but not substrate as its just plain messy and makes the bins heavy. If I end up really liking this setup, and decide to keep it, I may put some mineralized soil in it to play around with plants more.
As for the dewormer, its safe, I just don't know that its necessary. I am not a fan of prophylactic anything. I would ratehr let them sit in a bucket outside with daily water changes for a few weeks to get rid of pesties than use meds.