Where is a good level for the pH in my tank. What is too high and too low, and does pH do for anything else (i.e. alkalinity, hardness...)

__________________
-Kat

Guppies is not so much of a hassle when it comes to ph. Basically they accept a wide range of ph if acclimitised properly. The same goes for platy. Just remember moderation is always the best.

For a more complete answer on ph...well, I think Kev will be able to provide on that

For platies and guppies, keep your pH above 7 (between 7-8pH will be fine). Both fish are hard water fish and besides keeping your water pH on the alkali side with some buffering capacity can prevent your tank from getting any sudden pH crashes. I always prefer to keep fish in a higher pH tank than a lower one.

But if the pH is above 8 will that cause a problem? If so, how can I lower it?

__________________
-Kat

a pH of 8 would still be fine for many types of hard water fish. So the question back to you is, what fish are you keeping? If you're keeping Malawi cichlids, they'd thank you for that pH. If you're keeping Tanganyikan cichlids, they'd be hoping you push the pH up to 9. If you're keeping discus or Rams, they'd be very unhappy with you.

pH will gradually drop over time in an aquarium once the carbonate hardness (kH) is used up. There are things like "pH down" to lower pH, but usually I don't suggest you use these chemicals. Another way to lower pH would be to mix some deionised or Reverse Osmosis water into you fish tank (ie 50% tap, 50% RO water.).

If your tap water comes out with a pH above 8, and the fish you keep aren't critical about pH, I suggest you just leave it at that. It's too much hassle tinkering with chemicals and pH. In most cases, pH is the least of your worries. Worry about ammonia and nitrite b4 your pH.

I keep mollies and platys. The water does come out above 8, and I've lost a fish or two so I thought maybe that would be it... but some of the fish are perfectly fine.

__________________
-Kat

There are may ways ph can change in a tank. One of my ways to work wil ph levels is with a co2 system.

__________________
55g planted tank CO2 system, Eheim 2217 and internal Fluval 4, pinpoint ph monitor,30g Newt and Toad tank and a 2g Nano

LOL... of course a CO2 system will alter pH. I do believe our friend here is new at fish keeping so asking him/her to buy a $400 automated CO2 system to control pH is really throwing him/her in the deep deep end.

Don't get me wrong, ur suggestion works. Hell, I know it works, I run a CO2 planted tank as well.

I think he/she is asking for the basics.

Of course, if you wanna know more about CO2 systems, fire away..... :P

well, a DIY system is pretty easy and economical.......and safe as long as you follow a few safeguards....hmmm....but then again there's always risk of "CO2-ing" your fish to death...hehehehehe.

how about peat soil to lower the pH??? i guess it's pretty safe though you might get some colouring to your water.....

so kev, any better suggestion??????

I was thinking about the peat soil actually... but how much would it tint the water?

__________________
-Kat