The important thing about PH isn't so much understanding it, as it is knowing what yours is and needs to be. PH simply refers to whether your water is acidic, neutral or alkaline. For the beginner with 1 or 2 tanks set up you will more than likely have common fish that can live in a wide range of PH. If you have town or city water in this area your PH coming out the sink will be between 7.0 and 7.4. Most of the stores you deal with already have the fish in the same range so you should not have to worry about it at this stage. If your water supply comes from a well, spring, bottle or any other source then you really need to have a PH test done to find out what the number is.
PH is important for several reasons. The most important reason is if you take fish from one number to another it can kill them if done too fast, usually within 24 hours or less. This is called PH shock. Different fish can stand different amounts of change but even if they do it may weaken them and lead to them coming down, with disease in a week or two from the stress. The test is free, fast and this situation is completely avoidable.
How to fix the problem-- In most cases the addition of a product called Proper PH 7.0 will set your PH at 7.0 (neutral) and keep it there if water changes are done at least monthly and the product is reapplied to the new water as its added. This takes all the guesswork out. In a few cases I have found low KH levels. In this case your water does not have enough alkalinity and the addition of about ¼ teaspoon of baking soda to each 10 gallons and then Proper PH applied will fix this problem. The baking soda basically gives the buffer something to bind with and the buffer will then lock your PH at the correct number.
What if I want my PH at A different number-Many people want to keep fish in a different range. This is all right and can be important long term to breeding. The trick is to get the fish in the tank first and then adjust the PH gradually. It would be best to wait until all the fish are in the tank before you begin altering it. Once you have changed it all new fish will have to go in a separate tank and be acclimated to the new range slowly.
Raising the PH is easy. The addition of PH up or baking soda will do it in most cases. Some other choices are the addition of some crushed coral and synthetic ocean salt. Once you get it where you want it there is a Proper PH for that range that will help you maintain it. It comes in a 6.5,7.5 and 8.2 as well as the 7.0. The important thing to remember is that it's not good for the fish to have the PH fluctuating. This is not healthy for the fish and can lead to stress and illness.
Why should I buy a PH test kit? I may not always be available when you need the test done. Even with Proper PH you can overload the water with food or waste that can result in your PH dropping. Even town water isn't holding a PH for long in crowded tanks and everything that happens in the tank tends to make the PH want to lower. Just because your fish are alive does not mean your water is still safe. If it happens slowly many of the fish will get used to the lower PH and will not have a problem until you actually clean the tank. This results in clean water with normal PH raising the PH of the tank water and many fish will then go into PH shock and die. The longer you wait between partial water changes the more likely this is to occur. This can also result in new fish you just bought being killed.
My water coming out the sink has a good PH . Why should I worry?- just because
the test said the PH is fine does not mean it will stay that way. Many people have soft
water and low KH. After the water is in the tank the PH will usually begin to lower after
a day or two. In some cases it will fall rapidly. The ability to test it yourself allows
for instant monitoring and adjustments to begin immediately if necessary. I recommend
checking about once a week for the first few months until you get the feel of how your
water is going to behave. After that you can cut back to right before tank maintenance
time or before you release new fish. Its always a good idea to check when moving fish from
one tank in the house to another. I have killed fish by assuming the PH was the same. Two
tanks side by side maintenanced at the same times. One was at 7.2; the other was off the
chart on the acid side.
IMPORTANT! IF YOUR TEST HAS A READING AT ONE END OR THE OTHER HAVE IT DOUBLE CHECKED WITH A WIDER RANGE KIT. IT MAY BE MAY OFF THE CHART. GUESSING AND ASSUMING KILLS.
My water is hard alkaline water with high PH- The easiest thing here is to dilute the water with another source like distilled, bottled water with low KH and PH or run the water through a reverse osmosis or deionization unit. Water softening pillows will take out the hardness but will not lower the KH. The KH has to be lowered to get a lower PH that will stay put.