assuming we're only talking your water section...
substrate first and foremost is a decoration and an anchor. if you'd like it to be more that's an option but keep in mind the only substrates i know of that can be used as fertilizers (in a complete sense of the term) are aqua design amano's aqua soil or organic potting soil topped with sand or small gravel to keep it in place. if you use the potting soil it would have to e completely covered, amended with something to precipitate calcium (like crushed coral or sea shells) and the plants should pretty much stay put as long as possible to keep the soil from getting into the water. the soil will also seach tannins pretty bad at first. both of these options run the risk of having to be cycled so they don't release too much ammonia with your little guys in there too. on the other hand root tabs can be added monthly to the base of any rooted plants instead of using special substrates and it works well.
ferts are unfortunately possibly a necessity. the plants you pick, your lighting, soil and the nutrients in your water will play a big role there. also, if your water section will be very small there's less leeway since it can only hold so much and can be stripped of nutrients much faster. some people have successful planted tanks with inert substrates and just tap water. i call them lucky. you may be able to get away with it also, idk. if you'll be misting with r/o water and not adding tap water... just siphoning i'd say it's probably best to run the gambit on ferts, amend gh and so on.
i think aaron might be using msu ferts. that might be an option. also there's plenty of bottled name brand ferts that can be found at any decent local fish store. depending what your water's missing one or more of these products may be adequate for you. the last option is dry ferts... it's the one i use.
regardless what you use, if you use anything you'll be a chemist on a small scale in no time flat so don't be afraid of chemical names (believe me, it's a common problem). all plants need n (nitrogen), p (phophorous), k (potassium) and micros (things added in smaller amounts that can be grouped together). what i use...
n - kno3 - potassium nitrate
p - kh2po4 - potassium phosphate
k - k2so4 - potassium sulfate
micros - plantex csm+b
in addition, for my root tabs...
mgso4 - magnesium sulfate - epsom salts
fe - chelated iron
red mexican or red indian clay (it forms the tabs, hold the nutrients and the red in it is actually iron so it helps there too)
one thing to keep in mind is once you have all the chemicals they're only powders. so it's basically add this much of this powder and that much of that... no need to fiddle with remembering the compounds and such since they're printed on the package for reference. it's definitely not as hard as it sounds (i know it sounds like chinese now) and imho it's a lot easier than guessing with liquid ferts. dry ferts are a lot cheaper too since you're not paying for mostly water and to have it shipped/distributed here, there and everywhere across the country.
i don't know about reptsafe, personally. i do know that chemical reactions of certain sorts (especially those that may bind your ferts or minerals) aren't good for a naturalized environment such as a planted water section. i also don't know what the price works out to be in comparison on the reptisafe either. i don't think it would be an issue, but in the aquarium community the most regarded water treatment is prime. if you have any issues you can't pin down once you go planted in your water section you might want to consider only using proven methods... basically if you're using prime your dechlorinator will not be a question you need answered... and i can't personally answer it. once again, i don't THINK it's necessary but i don't know for sure.
adding critter to take care of algae or waste can backfire. bridgessi snails can add a good amount of waste themselves for a snail. if you experience algae issues the best treatments are usually clean your system (like a fish tank, not by washing it), get good water flow, lower your light intensity, give the light more distance to travel to the water by raising the fixture up, provide shade for any lower light plants the algae may be attacking or add ferts. the idea is to keep the plants happy and healthy. when the plants aren't healthy the algae will be. decaying plant matter is certainly a trigger for algae... so focus on the plants and the algae will be minimal.
if you don't like the brown water from the wood (there's nothing technically wrong with it) boil your wood and switch it with clean water often until your wood is no longer staining the hot water bad.
it is always better to dip or check your plants for any unwanted visitors/hitchikers prior to putting them in your tank. if you still wind up with a snail infestation you can try to keep less food from getting in there or trap them by putting food in there like squash or lettuce and removing it once it's covered in snails.
the quote at the beginning of this...
how it's done... favorite links thread ... goes into more detail with links to almost anything you'll ever need to know about growing aquatic plants. for more in depth info on that maybe aaron will link you to the thread i quoted that from if you ask nicely.
hopefully that's not too much to take in all at once.