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Candid Talk About Water Changes and How to Increase Their Effectiveness

Posted on Wednesday, March 16th, 2011 at 12:39 pm by
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I hear complaints from many hobbyist (who maintain their own aquariums) that they were told by their LFS that all they have to do is set the system up and do x amount of water changes and their aquarium will thrive with minimal problems arising. The customer says OK, that’s easy enough! They get the aquarium set up, 10% water changes are done bi-weekly, and six months later they notice their aquarium is just not looking as healthy. The reason: often a poor quality of salt is chosen, the newly mixed saltwater is never tested, dosing is done blindly, and the water changes were not in the ideal manner. In order to break this down properly, we will discuss salt, RO water, and ideal mixing practices in order to maximize your water changes.

Not all salt for making aquarium water is the same. Like gasoline, there are different grades and qualities which span a large price range. The salt you choose is the diet and baseline for your aquariums stability and health. The better quality you use, the better overall results you will have. When you use a salt with less than ideal content, the water change ends up replacing depleted water with less than sufficient “new” water. Over time water quality will slowly degrade until you have some type of “crash”. I am not going to dive deep into the topic about specific salts and differences at this time, that will come in another article. I recommend that you get the best salt you can with the budget that you have.

The large majority of hobbyist buy water from a store which uses an RO system, or have an RO/RODI unit at home that is used for making saltwater. This is great for getting pure water to mix with, however it strips the oxygen out of the water during the filtration process. Oxygen is important for the respiration of aquatic life in the aquarium. What most new hobbyist do: RO water is made/bought, salt is added and mixed in with a pump until the water is clear and then a water change is done. From the stand point of your aquarium, you removed stable oxygenated water and replaced it with unstable, de-oxygenated water thus creating stress. Let’s fix that!

So you have a high quality salt and some RO water and are going to do a water change so you can remove Dissolved Organic Compounds (DOCs) and replace depleted elements in your aquarium. Here are the best practices that I and nearly every experienced hobbyist I have spoken with uses… with great success!

1. Get you water and mix your salt in with a pump and an air stone. Why the air stone? to replace the oxygen that was removed by the RO unit. Then

2. Let the salt water mix and aerate for a minimum of 24 hours. As a general statement advanced hobbyist let their water mix and aerate for 24 to 72 hours before doing a water change. Why? you want the water to properly aerate and stabilize. When you mix salt water you are mixing chemicals that require a balance of ions. It takes time for the stabilization to occur, the majority of that process takes about 24 hours to occur. If you buy salt water from the store, aerate it for 24 hours before you do your water change.

3. Test the water and do your water change. Always test for temperature and salinity. If you are using a new brand of salt test the water parameters before you do a water change. The only way you are going to know how you are going to impact your aquarium with a water change is by knowing what is in the water you are using for the water change. Cheaper salts usually have less buffering (lower pH), lower calcium, and lower magnesium content than higher quality salts which can make a big difference. I recommend testing 5 things: salinity, pH, alkalinity, calcium, and magnesium. There is a huge accuracy difference between high quality and cheap test kits. Test kits and our recommendations will be covered in another article.

Lastly the frequency of water changes: Most people like to do large water changes however, for your aquarium doing smaller water changes keeps things more stable and balanced. For example, on my 185 gallon aquarium I do two or three 5 gallon water changes per week. This also allows easy maintenance because I am not messing with 20 or 30 gallons of water. I make some RO water, add salt and let is sit in the closet and mix for a day or two. I pull it out, test, do my water change and get 5 more gallons going. I never spend more than 10 minutes at a time maintaining my aquarium unless I want to get in there for fun. That correlates in more time to enjoy the tank and have a cold one!

Remember is it you vs the water and we are here to give you the edge.

Good luck and enjoy your aquarium.

For more information about water changes, check out What’s With Water Changes?

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2 Responses to “Candid Talk About Water Changes and How to Increase Their Effectiveness”

  1. Felicia says:

    I can’t tell you how often I talk to people who throw some salt in some RO water, mix it by hand, and then do a water change with it right away! Insanity!

  2. Kyle Thatcher says:

    Over mixing water causes precipitation of major elements if the element used to mix the water creates friction. High quality dehydrated salt mixes are typically pulverized to a smaller granule which dissolves faster. I have spoken to many manufacturers who suggest mixing until the water is clear. Synthetic mixes such as Salinity by SeaChem are a bit different, but I have been using Coral Pro by Red Sea for about two years and only had issues with the salt when I was mixing for 24-48 hours. Their lead developer scolded me for over mixing.
    The deposits left on pumps and buckets after mixing is evidence of over mixing if it had occurred.

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