Good luck to both of you with fishless cycling your new tanks!
Amy:
A common approach is to use laterite under sand or gravel for planted tanks, there are also many different sorts of aquatic soils that can be purchased. For the more hardy plants, you don't really need a special substrate. I've got a tank with just sand and one with a layer of peat, soil and sand mixed together and a layer of sand on top. Both have similar plants, I get better growth in the tank with soil especially from heavy root feeders, the same plants in the sand only tank get root fertilizer tabs but both grow well enough for a low tech, low budget tank with a focus on fish. The planted forum has tons of information on easy plants, lighting, fertilization and substrates if you want to look into it more.
Anything found on the ground outside somewhere is best boiled before you stick it in a tank. Coral however will likely raise the pH in your tank, you'll want to avoid it. If you find any rocks or purchase some gravel at a hardware store, test it with vinegar first to see if you get a reaction. If you do, don't use it in your tank as it will raise the pH. Shells should also be avoided.
scorphonic:
When adding water to the tank for the first time it doesn't matter if you get the chlorine/chloramines in your filter, these are only dangerous to bacteria and fish and you won't have any to kill when filling up your tank for the first time. The easiest way is to put in your substrate and arrange your decorations, then fill up with water and treat the tank once it's full. When you do water changes, there are two schools of thought. The safest way is to treat the water before you add it to the tank, I'd definitely do this with a new tank. Once you've had a mature tank running well for months, many people will just dump the chemicals into the tank and fill up the tank with water. I've done this for years without any harm to my fish or filter, it's much easier to do with larger tanks as you can drag in a garden hose and fill them up from that. If you've got a small tank or a large >30% water change, it would be best to treat the water first though.
You can get yourself some buckets for use only with your fishtank and a syphon of a suitable size for cleaning, or you might try a Python cleaning system. I've personally never used one, but they will syphon water directly into your sink and allow you to fill from the tap. If you've got plants they love dirty fish water too, I always use it on my orchids and other potted plants, never have to fertilize.
The blue lights you have sound like the actinics used for marine tanks. They really don't have any use in freshwater but they won't hurt anything. Generally if you're going to add moonlights that has to be done seperately, though I'm not terribly familiar with the Juwel tanks.
