Aquarium Water pH

Don't be fooled by the small numbers..........

Aquarium pH is measured on a scale of 0-14.  The Zero is the highly acidic end of the range and 14 is highly alkaline. 

Seven is round about neutral but interestingly an aquarium pH level of five is ten times more acidic than a pH level of six so small changes in the numbers mean big changes in the water conditions for your fish.

Most fish thrive in an aquarium pH range of 6.5-7.5 and can be happy outside of these parameters.  What all fish hate and what will cause them more stress and harm is sudden changes in pH levels.  Many aquarists keep fish successfully in pH levels outside of their ideal.  The important thing with pH levels is to try to maintain stability.

If you move on to keep fish that need a specific water pH level then you need to swot up on the subject and understand it more fully but for most starter aquariums you just need to monitor pH levels and react to large changes which will be rare if you are keeping to a regular maintenance programme.

Most tap Water has a pH range that falls within the desired 6.5-7.5 range simply because to go far out side this would be harmful to humans, never mind our fish.

If you want to test your local tap water simply allow a cup of water to stand for a day or two before testing.  You will find that if you test it too soon it can give a false reading because of gases suspended in the water!

Test the water in your aquarium a couple of days after setting up and test it again after the Nitrogen Cycle has kicked in.  This will give you a base line to work from.  Assuming that any water change is likely to involve adding tap water, it will also give you an idea of what effect water changes will have on pH values.

Bear in Mind.....Your local pet store has probably already acclimatised the fish they sell to the pH level of the local water so if you start messing with the 'natural' pH levels you are likely to simply end up stressing your new fish.  Don't get too hung up on aquarium pH and spend hours trying to change it.  With a few exceptions, most fish live happily in quite a broad range of pH levels.

What can change pH levels and what to do about it

You do need to monitor aquarium pH levels because it is an indicator of other potential problems.  Falling pH levels is an indicator of declining water quality usually due to in adequate water changes so do a partial water change to get things back to normal.  If pH levels have changed a lot then do several 15% water changes twenty four hours apart to adjust pH levels gradually and avoid pH shock to the fish.

Increasing pH levels may be due to a chemical reaction with calcium based gravels or decorations slowly dissolving although hopefully this will have been avoided through careful choice of substrate.

Remember the Golden Rule - NO SUDDEN CHANGES IN pH LEVELS