how do u keep ur ph in the proper ranges?

A calcium based subtrate or alot of calcium based rock (such as Tuffa) can help stablize PH to some small extent, however reqular water changes and a good salt mix are usually the best bets for maintaining PH, also alot of algaes can raise or lower PH due to photosynthisis.

Depending on your fish collection, most tanks of community fish the ph should be 7...7.2...in that range. I have Discus and they prefer more acidic water. Regular baking soda will raise ph...do it slowly.....also buying ph up...or....ph down is a good idea and follow directions.

There is this stuff that my lfs recomended I should buy that automaticly levels the PH to 8.3 for instance. There are different bottle you buy for a particular PH and this way you add I think it is 2 teaspoons a weeks for 1 month, and then it will stabilize. I am going to buy it soon so I will be able to comment on it. It sounds good though because using PH up ad Down can be a hassle. check the product out, might help and it isn't too expensive. The bottle he recomended was big, he said it would last for quite a while and it was 22 Australian dollars.

In most cases, what you need is:
*strong circulation, which will reduce CO2 in the water
*decent stocking and feeding habits to keep organic acids under control
*proper alkalinity (3-5 mEq/L), which buffers the water at the right pH; depending on the tank, this can often be maintained with regular water changes. Sometimes you will need to add buffer. Don't add buffer unless you test your alkalinity first.