Understanding Water
A gallon of water weights approximately 8.34 pounds. This is important as it adds to the weight of the aquarium. If you have a 10 gallon aquarium, the weight of the water alone would be over 80 pounds, minus substrate, filter and decorations. Because of the weight, a strong stand, built specifically for aquariums is the safest choice.
Municiple, or useually called Tap water will useually contain chemicals that are harmful to aquarium livestock such as flouride and chlorine. This means that the water will have to treated in order to neutrilize these chemicals. Knowing your municiple water, such as what the pH will be when it comes out of the faucet, can help you prepare treatments and make any necessary adjustments.
Water from a Well is typically much safer, and unless treated before entering the house as some systems will do, should contain useful vitamines and minerals for your fish. However, some areas will present a higher or lower pH just depending on the soil around the well. Know what the pH, KH, and GH is before adding to your aquarium.
Another common means which to treat water is with Reverse Osmossis unit. These will remove all impurities from the water. However, you must then treat the water to restore essential vitamins and minerals. RO water will often come out acidic, as it has to means which to buffer against pH swing. A benifit to RO water is that it can be economical for hobbiests who have multiple tanks.
pH is the measurement of how Acidic or Basic water is. Most aquarium livestock and plants prefer a pH of around 7.2, but some species prefer more acidic or alkaline water. This is why is important to understand the livestock you want to keep before setting up an aquarium, as well as knowing the water you are using before adding it to the tank.
Smaller aquariums are subject to rapid changes in temperature, while larger bodies of water hold heat for longer periods. These rapid shifts can affect fish and plants. Without a source of heat, water will always rise or fall to the ambient temperature of the room.
**Low Alkalinity can allow your aquarium to go through wild pH swings. Alkalinity can be lost by using Reverse Osmossis water. Normal ranges are around 150-300 mg/l