Freshwater aquarium setup usually involves a very direct and simple process because basically all you need to do is to dechlorinate the water and ensure that the water chemistry plus temperature is roughly similar to the fish tank before you can add in the water. Freshwater setup sometimes allow up to 50% addition of new water in a single change and the temperatures and water parameters doesn’t have to be exact because these variations can easily be tolerated and acclimatized by the fish.
However when it comes to saltwater aquarium setup, the routine becomes more tricky because you have to avoid doing large water change at any particular time. The reason is because the marine fish and invertebrates are more sensitive to changes and if this is not done properly it could upset the ecosystem.
Usually water change of maximum 5% is allowed at any single time for saltwater tank. First, get a container large enough to accommodate the total amount of the water you need to prepare. Fill in fresh water and after the normal process of dechlorinating using heavy aeration, you need to mix in the aquarium salt according to the manufacturer’s instructions. Freshly prepared new saltwater can cause serious burns and during the water preparation, I would suggest you use goggles to avoid splashing into the eyes. Wear aprons if possible for safety purpose. Upon completion, leave the newly mixed saltwater in the container for at least 24 hours.
After this is done, then comes the tricky part. Basically what you need to do is to ensure that the salt concentration in the aquarium water falls within the range of recommended limit for saltwater aquarium setup. In order to achieve that, first measure and determine the specific gravity of the water in your saltwater tank by using hydrometer or refractometer. I would suggest using refractometer because it gives a more accurate reading. Next, do the same as well for your new water, which you have already mixed in the marine salt.
Once you obtained the reading for both, make a simple calculation to determine whether by adding in the amount of new water, will this cause the final density in the actual tank to fall or rise. If you find that specific gravity is too low in the saltwater tank, make a rough calculation (based on percent difference) to prepare the new water with higher density by adding more salt to it. Your final objective is that, when you mix in the new water, this will cause the density in the main tank to rise. Don’t worry about not getting it right the first time because you can always do adjustments if needed.
Finally, before adding in the water, make sure that protein skimmer and aquarium filter has been thoroughly cleaned. After the water has been added in, reconfirm on the final density of the aquarium water to determine whether you have done it correctly. Experienced aquarists are known to keep another batch of new water in case there’s an emergency whereby there’s an urgent need to quickly do a water change. The reason behind this is very simple, you don’t have time to immediately prepare the water and as such it is best to have a standby new saltwater on hand when it is needed.
Common saltwater aquarium problems and approaches:
Guide on how to effectively deal with marine green algae bloom