What is pH?

Q. What causes sudden changes in pH?
A. Usually sudden pH changes occur through human interaction, common causes are water changes, additives, chemical filter media and aquarium décor isn’t inert. It is always a good idea to make any changes slowly to an aquarium and monitor any change. Removing a chemical or adding a chemical will always have an effect and sometimes the knock on effect is not beneficial!

Q. What causes pH swings through the day?
A. The pH equilibrium is influenced by many things in the aquarium; one of the main contributors is plants which use CO2 present throughout the day during a process called photosynthesis. CO2 is a gas dissolved in the aquarium water and that makes it more acidic, when plants have no light CO2 starts to build up and lower pH. Low pH aquariums with large amounts of plants and high light levels will generally see greater swings.

Q. What controls pH swings through the day?
A. Daily swings in pH are common in the aquarium and can happen for a number of reasons. The size of the swing is usually controlled by the hardness of the water (dkh). This means marine systems will see very small swings as they have high buffer capacities, however soft freshwater aquariums (especially Amazonian or black water tanks) will react greater to changes in ion equilibrium as they have little buffer system to resist change. If you want to reduce swings in pH a good way is to slowly introduce some buffers.

Q. Why doesn’t my seneye match my digital probe or test kit.
A. The seneye uses the latest optical techniques to measure pH whereas most hand held probes use electrical currents. We have found that all systems work very consistently when they are in a high buffer solutions (such as sea water) but when the buffer solution gets weaker (such as in Amazonian tanks) the probes start to move away from each other and become inaccurate. We have found that cheap probes seem to pull high and expensive ones seem to pull low when compared to the seneye.

Q. What is more important absolute pH values or change.
A. The answer is most fish are happy in a pH range but almost all live stock hates change. This is why fish are very vulnerable when they are brought home from a shop or transferred from different systems. For this reason it is important to not get too hung up on striving for perfect pH, especially if the fish are healthy. It is more important to watch for sudden large change or gradual change over time (both of which the seneye is very good at).

Q. My ammonia test kit shows 0 but my seneye shows ammonia.
A. Most ammonia test kits measure total ammonia and only at very high levels. They often have no way of indicating low levels of NH3 so cannot be compared to a seneye.

Q. My aquarium shows a very low pH and it’s below 6.4?
A. Often in an aquarium Black water and Amazonian tanks pH can very low the seneye doesn’t measure below 6.4 but if the aquarium does creep up seneye will be sure to let you know.