GSP Perfect water conditions

[ScubaPuffer]

Hello! Can anyone tell me the optimal ranges, for a GSP tank of:
PH
Ammonia (0.0 I assume)
Nitrate
Nitrite
Alkalinity

Also, if they levels are too high, what can I do to lower the level that is too high?
I couldn't find any artcles with all this info together on the internet--I imagine I'm no tht eonly person who would find all this info helpful.
Also - For the bonus points:

If I use a SW testing kit for FW, or vice versa, how will this skew my results? I currntly have a Instant Ocean "all in one aquarium test kit" my buddy gave me, and the "chips" say "SW".

Thanks!!

[ScubaPuffer]

I have a brackish water conditions for Spike and Spot (GSPs) by the way (1.006 sg because they are babies) well, technically they are juviniles.....they are under 2".
So far they are really happy and awnry, brightly colored with plump little bellies, so any help with the water conditions so I could make them even more happy would be greatly appreciated.

[crazedpuffer]

PH Around 8 when full grown. Fish adjust easy to PH so I wouldn't worry about it though, and altering PH often does more harm then good.
Ammonia 0.0
Nitrate Less than .40 ppm, preferably less than .10 or .20
Nitrite 0.0
Alkalinity The fish adjust rather easy to this too.
If the levels are too high, Water Changes.. Don't use chemicals, just water changes will do the trick!

The results normally don't work right. It might look like the water quality is perfect and it's bad, or bad when it's perfect.

[StormySkiez]

This may help you as well: ug.php/v/PufferPedia/Brackish/T_Nigroviridis/

[ScubaPuffer]

Cool. Thanks for the help. Sooo...basically, except for the ph, all levels need to be as close to 0 as possible.
I can do that