The best way to test the amount of dissolved oxygen in your aquariums water is by using a portable dissolved oxygen meter. After calibrating this meter, you can then place a probe into the tank and read results on a digital display.
Meters will often express the results as a percentage of dissolved oxygen per liter of water. This means of testing however, is expensive and is not available to everyone, an alternative is to use a chemical test kit, which works fairly similarly to other types of test kits, such as PH level readers.
If you want to try out the chemical test kit, go for it, but be sure to do some research on them beforehand as some can be very flawed, and no one wants that.
Another good way of testing this is to look at your fish and see what they are telling you in their behavior. If there is not enough dissolved oxygen then your fish may be swimming at the surface as they gasp for air, or hang out around the output filter.
How do I manually add oxygen to my fish tank?
Most of us will have filtration systems, however, if a power outage strikes, you may not have the power supply to supply the much-needed oxygen to your fishy friends. Knowing how to manually oxygenate your tank in the case of this is very useful.
You can do this in a few different ways, but one of the easiest ways is to pour water into the tank from some height above.
The water will pick up air as it falls, the amount of the oxygen picked up will depend on how high above the tank you pour the water from, and how many times you repeat this procedure. The more you do it the more oxygen you will pick up.
To do this, simply take a pitcher, or cup, and clean it out, then fill it with aquarium water. Hold the filled container as high as you reasonably can above the aquarium and pour the water back into the tank, repeat this process over and over again until your fish seem more happy with their oxygen levels.
There is no hard and fast number of times you should do this to reach the right number of times, it is all up to you and the fish.
Can you put too much oxygen in a fish tank?
It may seem odd that there could ever be such a thing as too much oxygen. However, it is perfectly possible to have too much oxygen.
If there is too much oxygen in your fish’s tank aquarium water then it can actually lead to a potentially lethal gas bubble disease.
This is a disease in which gas comes out of the solution inside the fish which creates bubbles in its skin and around its eyes. Which is really rather horrible. However, excess nitrogen is a much more common cause of this than nitrogen is.
A more common problem is that there can be too much aeration, this would mean you would end up seeing your fish being whisked around the aquarium, or your fish would be struggling a bit.
Remember that your fish tanks aeration needs to be matched to the temperature of the water as well, warm water needs more aeration as it does not absorb as much as cold does, in this case warm water will need more air, but cold will not need as much.
Does the aquarium filter provide oxygen?
Water filters help a great amount when it comes to increasing oxygen in water, they cause water movement at the surface when oxygen exchange occurs.
Filters take in water at the bottom of your tank, then push it up and release it into the aquarium at the surface, distributing oxygenated water the whole time.
You should ensure that your aquarium is properly functioning at its fullest capacity. Filters can get jammed or blocked, so if you believe your fish are not getting enough oxygen take a look at your filter and check for any blockages.
Most of the time if you find no water is flowing through it, and your fish look like they need some air, all that is required is a good cleaning session on the filter.
If you even more oxygen, add an additional filter, or replace the existing filter with a high capacity one. Increased water movement will increase oxygenation.
You can also use a power head, a spray bar o the outlet on a filter, or use air stones. All that water needs to aerate is movement, a waterfall will aerate a pond, a filter will aerate a tank, or simply using a cup to create a mini waterfall if the filter doesn’t work.