Water is with no doubt the basis of an aquarium system and even though everything about it seems quite easy, it is so unfortunate that this is where most new hobbyists usually get it wrong. There are different water sources for a fish tank or aquarium that you can use. The main choices include getting the water from the ocean, tap water, de-ionized purified water or reverse osmosis, bottled water, softened water, collected water or rain water. Before you embark on using any of these water options, there are things that you must understand very well.
Good water quality plays an essential role in any healthy aquarium. The truth off the matter is that if the other aspects of your aquarium are good and your water quality is perfect, you shouldn’t worry about your fish and other organisms in the aquarium as they are certainly going to look and take care of themselves.
The salinity of an aquarium refers the amounts of solids dissolved in the water or in other words; it is a measure of the saltiness of aquarium water than freshwater. When you are making salt water for your aquarium, there is no point of making the water as salty as you possibly can since you will soon be throwing away your cured water rather quickly. One thing you should keep in mind is that a fish only tank can benefit more water with lower salinity while reef tanks with inverts and corals will do well when the salinity is on the high end of story.
Keeping the salinity value of the water steady and constant is very important and will enhance the success of your aquarium in a major way. Some aquarium hobbyists prefer keeping the salinity of their aquariums low since this helps to inhibit growth of parasites which can cause diseases. This is however not a recommended option as it can make the conditions in the aquarium uncomfortable and stressful.
To ensure that the salinity of your aquarium is not up or below the scale, you will need to measure salinity. This can be done by using a hydrometer or a salinity monitor/ salinity refractometer. Hydrometer is more preferred since it is an inexpensive option and still very effective. It consists of a clear container made of plastic and a floating indicator in it. When water is added, the floating indicator shows the specific salinity on a scale.
For saltwater and reef tanks the best choice would be to use filtered ocean water. As this in not a viable option for most aquarist your next best choice is to use Reverse Osmosis or Reverse osmosis with deionization which will get the TDS (total dissolved solids) to zero or near zero. You should never use tap water for your aquarium! Tap water contains chlorine which will kill everything. If you use tap water you must treat it for chlorine. The other issue with tap water is it also contains potassium, phosphorus and other chemicals that promote algae.
Using Reverse osmosis water will alleviate headaches in the future because of the chemicals in municipal and well water that promote algae. Reverse osmosis is a method of water purification whereby you are able to effectively remove the impurities in the water and other particulate as well as eliminating some ions to neutralize the water PH. You just need to top off evaporated water with RO water as salt does not evaporate. While making a reverse osmosis set up at home is relatively easy, this might prove to be a little complicated and you are bound to make some mistakes that could compromise your entire aquarium. As such, buying one from the stores is more convenient and will help ensure that everything is fine.