I hate to waste space here with one small question, but I am finding it
hard to find my same questions with the search method, and i am sure
that its been asked before. so sorry in advance.
No need to apologize, we're here for advice!

anyway I will ask a couple questions I cant find.

so here they are, first do I have to turn off my filters when I do a water change? and just to help me
why? if I do.
No need to turn off your filters during maintenance, as long as the waterflow isn't interrupted. My canisters stay on all the time during maintenance.
My sump will start to pump air if i do a waterchange, as will my HOB's, so i turn those of during maintenance.

also my water doesn't smell how do I say it.....fresh, its kind of smelly not make you through up bad
but kind of stinky, is this a normal thing or am I doing something really wrong?
My tankwater smells like algae and bacteria if i open the lid.
It's a kinda wet-ground smell.And my water will smell fishy, for the Gar eats dead fish.I kinda like it. It shouldn't be a rotting smell though. If it starts to smell like rotten eggs, you may have ammonia problems or food leftovers rotting somewhere.A thick layer of gravel or sand can create pockets of bad gas, but vacuuming thoroughly will usually help against that problem

and when I do my first filter cleaning do I change all the media in my filters? or just some carbon and some
of the little white rock like things that come in a fulval filter, I have two a 450 and a 250 the 250 I have
buffing pads in the bottom chamber, do I just clean these or replace them straight out? or leave them alone.
I clean out and rince any spongues, blue filterfloss and filterpads in old tankwater every other month or when things get clogged.I hardly ever replace any of the stuff.I do use white filter cotton as prefilter and this gets changed every week!
The stones and ceramic rings stay mostly untouched.
Carbon should be disposed of after it has served it's purpose for some months, and should not be reused.It will leak back the adsorbed toxins if used for too long.

and just because I have ya here, I said in another thread I was baby sitting my friends oscar
while he cycles his new tank, my O relentlessly pick on the other O, I have read here thats normal
but its quite disturbing to say the least. however when my O isn't picking on the other O
they lay under the log head to tail and chill, anyway the question is should I evict my buddies O
more rapidly?
I say keep a close eye on them. Some aggression is normal, but if there's signs of real or possible permanent damage, you should act and put him in another tank.

anyway thanks again
Your welcome, i hope this helps.
Zoo