iron and phosphates (it might be potassium... i always get that mixed up) can bind becoming useless so dosing micros and macros are usually done on separate days. it's not absolutely necessary... i dose mine together.
if you went crazy dosing i guess you could kill fish... not likely and i think the plants would be fine at even higher doses.
a well rounded diet is definitely important. anything missing causes issues. if it's not already in your water - dose it. if you're not sure - dose it. it can't hurt too much.
big w/c = 50%
dry ferts vs. seachem... price of month of seachem is probably more than price of year of dry...
if your gh is low... get barr's gh booster
definite necessities...
kno3
kh2po4
plantex
best to have anyway...
k2so4
sometimes useful, but not for everybody (you'll typically need very little)...
chelated iron
things you'll probably want also (but will locate locally for very cheap)...
red mexican clay or red indian clay
epsom salts (if necessary)
baking soda (if necessary... usually isn't)
you will know how to dose by trial and error. there's directions for every kind of ferts a person can buy somewhere... and many different directions for each. even with seachem's "foolproof" directions most people find it necessary to "tweak" dosing according to their tank. for dosing dry check the sticky in the planted section... and
www.barrreport.com. make sure any rooted plants get root tabs also. riiz wrote up a recipe that's in the sticky... works great imho.
when your plants grow big, happy and healthy you can sell your seachem ferts here to someone who still swears by them... as well as your excess plants.
bob (mgamer) is a good guy with a good rep. you can buy them from him, aquariumfertilizer.com, rex grigg or greenleaf aquariums. greenleaf will be the most expensive and aquariumfertilizer has the best rep/prices/been around the longest afaik. keep in mind i have not tried or checked bobstropicalplants yet. if you are going to get plants at the same time that might be your best bet.
pet shops NEVER sell the best stuff... unless it's a place that's often mentioned and highly regarded around here for the most part... for dry ferts... order online.
i hope i've covered everything.
