pH is one of the most important aspects of maintaining a properly balanced aquarium. In this section we will explore the best ways to manage pH levels, best practices and we will debunk some myths of pH management.

What is pH?

Generally pH is referred to as a measure of acidity, but in order to avoid confusion we will here instead refer to it as a measure of neutrality of water. Think of a scale, with the balance point at 7 (or neutral).  1 is the most acidic and 14 is the most base, the common misconception when pH is referred to as a measure of acidity is that higher means more acidic, which is false and can lead to dead tanks. So to recap 1-6.9 is considered acidic and 7.1-14 is considered base. Rarely in and aquarium will you measure anything outside of the 5-9 range as very few things thrive or can survive beyond those parameters.

Best Practices

The best way to maintain pH is to manage your tank in such a way that there are not many things that will change the ph one way or the other, or to have several things that have very minor effects on the pH that balance each other out. The best way to do this is to set a goal pH before you even put water in the tank and then determine how everything will effect the tanks pH before you put it in the tank. This means that impulse buys are generally out and the tank needs to be planned before you start. Substrate, rocks, driftwood, CO2 injection, decorations, plants, aeration, temperature, water treatments, food and anything else that you put in your tank all affect your water and the pH of the water. The lower your kH the easier it is for the pH to rapidly change, but lower kH is required for many shrimp. The easiest way to test things like how food will effect the water is to take 1 cup of tank water and test it, then add a small amount of food and let it set for 6 hours stir and test again. Ideally whatever you are testing will have no effect on the pH of your tank water. If it does have some effect then you need account for that in your tank.

Raising & Lowering  pH

The suggestion that everything should be done naturally is generally a good one, when it comes to long term pH adjustment. When you need a short term pH fix I would always go with chemicals designed for adjusting pH(assuming they are safe to the creatures in the tank). To many “natural” products have unintended side effects.

Myths and Misconceptions

Just because something is natural and acidic or alkaline does not make it safe or correct for altering the pH of aquarium water, in this section we will cover some of the myths and misconceptions that can result in serious spikes or bouncing in a tanks pH. For instance it is sometimes wrongly suggested that lemon or lime juice should be used to lower pH, while these will both immediately lower pH as they are exposed to water they will being to oxidize and will then go from acidic to base and increase both pH and Alkalinity this can cause a very dangerous rebound effect in the pH and livestock sensitive to large changes in pH could be adversely affected. Additionally vinegar is also sometimes suggested as a way to lower pH, but vinegar has the effect of being particularly good at killing bacterial and can partially reset the nitrogen cycle, while normally okay for fish this can be lethal to shrimp. It is my advice to achieve a pH balance before adding livestock and only use things that slowly change the pH of the water and only to your desired balance point. If you must use something to change the pH of the water more rapidly then I would recommend using chemicals designed to change the pH and avoid natural remedies or other around the house fixes. (Baking Soda is an exception so long as you know the total effects on your water)