which test is the most important?

[Splendid]

lol ha!

[Cartman89]

I think they are all important but pH gets my vote because out of wack pH or even the slights pH drops can kill fish.

[Frankie]

I dont test for ph. i have a pinpoint that dose that for me.

[Boomer]

because out of whack pH or even the slights pH drops can kill fish.

In 30+ years of running tanks, house, university, zoo's, LFS, I never seen a fish die due to a pH whack, let alone slight pH shifts. You may want to check the pH of a shipping bag sometime. Sometimes they are so low you would s_hit your pants. That little bag and that fish pushing out all that CO2 with no place for it to go but into water. Mater of fact, shipping bags for fish, to include marine fish, can be supersaturated with CO2. pH's in the 6's or even lower at times. And all that O2 in the bag, even makes it worse, as it causes a dysfunction of the Bore and Root Effect ( a blood chemistry thing).

[Cougra]

Originally Posted by Cartman89

I think they are all important but pH gets my vote because out of wack pH or even the slights pH drops can kill fish.

I agree with Boomer on this one in that slight pH shifts aren't that harmful. As a matter of course you're pH shifts throughout the regular day/night schedual of a tank as photosynthesis adds and depletes the CO2 in the tank. pH in a regular aquarium can shift as much as .3 in one day without any signs of stress on any of the animals. To see this you can easily test the pH in the morning just before lights come on (it should be at it's lowest) and in the evening about 1/2 hour before the lights go off (it should be at it's highest). I feel we test pH more to make sure that our water chemistry is in balance as there is a direct relationship between pH, Alk and Calcium.

[Splendid]

thanks guys and check out my sig. i will update my predator tank on my sig. when we get it more setup!