Water parameter advice

What should I aim for guys?
And what are the most important?
One more for you guys, I have lined up a 4+18+18 as a give away,yeh nothing better than a freebie.
This one has a 6 mil base, is that strong enough?

I was hoping some one else would say something,slackers!

Ammonia should be 0 at all times, if you do get a reading, add some ammo lock for a day or so and PH buffer,be sure the skimmer is doing it’s bit or at least get some water surface tension being brocken, that helps a lot.

Nitrites should always be 0 after you have matured your tank, this is a health issue similar to ammonia poisoning as it gets into the fishes blood and increases methemoglobin and renders oxygen a little useless and stresses them seriously as they suffocate internally until death.

Nitrate can be as high as 20 and even 40,but if you can, check just after the water change, if it is below 5 to 10,the tanks doing fine, if you want 0 you will have to put in a remote deep sand bed or nitrate reactor, you can build your own.

Kh,carbonate hardness, this is the alkaline buffering capacity of the tank water.
The fishes body is more or less alkaline naturally and is constantly bombarded by free radicals that are normally acidic and with good KH-translated into good Ph,these do not create much of a problem in that kind of environment.
They are finding the same issues with in humans these days, magessium is a great fighter of that.
There is no particular level needed of KH, though the ocean is normally 7ish,so try for 7 to 10,but more importantly, it should remain stable at a level above 7 if possible, stability is a must.

PH, potential or power of hydrogen, this should be stable at any where from 7.9 to 8.4,stablilty is a must!
Fresh rainwater, though it has some natural nitrate in it, is supposed to be 7.0,neutral PH.
Low PH allows free radicals to attack of your fish and the acidic type of environment stresses them via affecting available oxygen.

Temperature should be for temperate life forms,20c to 25c,tropical from 24c to 28c.

Calcium 320-400 for fish only and 400-480 for reef aquariums ppm

Phosphate, try for reef aquariums,0.5 down to 0.1 ppm

Magnesium 1200 to 1400 ppm

Iodine from iodide-0.04 to 0.10 ppm

Strontium,say 5 to 10 ppm

Salt levels (specific gravity) for fish only .18 to .25,for corals never below .23 for prolonged periods or above .26

That’s all I know, these are what I used to aim for back in the day when I used to test water parameters.