Dont clean you filters out in tap water clean them in old tank water when you do a water change
Dont change more than 30% of your water at any one water change as this can cause the chemistry of the water to change if you have a major problem with water quality then it is better to change 15% on a daily basis
Dont put raw tap water into your tank(s) use a dechlorinator because the chlorine in tap water will kill off the benificial bacteria that you have built up
Dont forget to reserch the fish you want to buy as that nice little cute fish could grow bigger than you realise i.e. the common plec will grow 20"+ also will it go with your other fish instead of IN them, is it a schooling fish
Dont forget to give your gravel a good clean every so offten use a gravel vac (unless you are using under gravel filltration then just rake it periodically or you run the risk of removing the benificial bacteria) if using sand as the substrate rake it through every couple of weeks
Dont use sand with an under gravel fillter it will just clog it up
Dont play with the PH of your water it might not seem much to you but it is to your fish most PH modifying products fill your tank with algea enhancing phosphates
Dont miss spell nitrite its NITRITE its poisonous to your fish one vowl wrong (nitrAte) and you could kill all your fish
Dont put salt in with corys, plecs or loaches no it wont burn the skin as some people think but it will upset the osmoregulatory system of the fish
Dont overstock your tank 1" of fish (not including the tail) per us gallon is a good rule of thumb to follow but also take into consideration the depth of the fish i.e. dont keep angel fish in a 10" high tank (unless you are re-shooting jaws)
Dont turn your filtration off for any longer than necessary as the benificial bacteria will start to die off. so no switching off over night cause its to noisy
Dont overfeed feed little but offten any food uneaten after 10 mins means you are overfeeding in worse case's of overfeeding the water will turn cloudy also the little catfish you bought to hoover the bottom of the tank has its own dietry needs as well
Dont be afraid to ask for help or advice (but read below)
Dont believe every thing you get told (including this if you want) just because it works for me, dont mean its guaranteed to work for you, neither is every thing you read (remember fish cant read) its just somebody else experiances and oppinions

i was going to say u'd made a few mistakes in the ur post, bold bits etc, but u must have been editing it as i was trying to 'help' lol. too quick for my own good again.

That's very pessimistic !

Is this the point we ask Clunkster wether he's a 'glass half full' or a 'glass half empty' person ?

I'll tag this Topic for the FAQ.

half full