How long can water sit before using for water change?

dmschiff

Member
I know water should be mixed at least 24 hours prior to using for a water change.
My question is: once mixed how soon should it be used? 2 days?1 week??????
 

coachklm

Active Member
straight from LEE....
1. Make sure you're using proper source water free of contaminants (including but not limited to: dissolved organics, ammonia, nitrites, phosphates, nitrates, silica compounds, smell, and poisons). If there is any doubt as to the quality of the source water, test it. Artificial salt manufacturers who recommend using tap water as the source water are wrong. The variations on tap water around the world make it such a wide range of ingredients in tap water, that tap water isn't consistently reliable enough for source water for the marine aquarium.
2. Mix the source water, preferably using a submersible (inside aquarium) pump (not an aerator). The water should move up and down in the mixing container, not around in a circle. [Adding air to the water is not desirable, IMO because it encourages carbonate precipitation as the water is encouraged to keep taking on air.]
3. Add the artificial salt to the water, in the quantity required to get close to the marine system's (or QT water's) specific gravity.
4. Mix the salt according to the salt manufacturer's directions (as to how long to mix). (NOTE: The salt manufacturer should know how best to mix their salt into water, however studies have shown that the most stabilized water is achieved after about a week of mixing. This extended time is connected to gas exchange and the chemical reactions going on in the water between the various salts and the gases in the surrounding air.) In no case would I recommend mixing for less than 48 hours.
It has been discovered that bad salt mixes will usually 'show themselves out' within the first 48 hours of mixing. If the mixed salt is cloudy or undissolved in 48 hours, there is something wrong. (NOTE: Some unusual/less common artificial salt manufacturers may depend upon mixing to chemically react their chosen ingredients. Such manufacturers can recommend up to and including 2 weeks of mixing!).

5. After mixing is complete, check the specific gravity of the prepared water. [NOTE: If the salt mix is not properly balanced to provide the proper calcium, alkalinity, and magnesium, now is an opportunity to bring those chemistries into the desired range with the chemistries in the marine system. This is optional.] The specific gravity of the new water should match as closely as you can with the specific gravity of the water it will replace. Usually, matching to within 0.001 sp. gr. unit is acceptable. Adjust the new water by adding a little more salt, or adding some source water. If a lot of salt had to be added (more than 2% of what you've already added) then go back to 4.
6. When the specific gravity of the new water matches the marine system water specific gravity, measure the pH and temperature of the marine system and the new water. Adjust pH and temperature of the new water to that of the marine system water. (NOTE: This is one of the places of the biggest common error -- the pH adjustment. The pH of the new and old water must be extremely close -- to within 0.05 pH units, if possible). The temperature of the new water should be no lower, and can be up to 1.5F higher than the marine system water.
7. Remove the water from the marine system. You can take advantage of siphoning in order to clean out detritus/debris around in the display tank, sump, substrate, and/or refugium.
8. Add the new water to the marine system.
After the above, it is important to replace evaporated water with distilled water (if you have a small aquarium), or RO/DI or deionized water for larger systems. Maintain a constant specific gravity of the marine system, a constant pH in the proper zone, and a constant temperature.
 

coachklm

Active Member
and some tidbits...
Some interesting information and things to know:
a. A sudden drop in temperature as little as 2F in an hour can cause a marine fish mucous coating to sluff off or improperly function. This causes the fish to become sensitive to infection and diseases it could otherwise fend off. This is the reason why fish who go through a drop in temperature suddenly become ill or infected. A small drop in temperature is significantly far worse than a small rise in temperature.
b. pH is measured not in 'straight numbers' but in a logarithmic function of the hydrogen ion concentration. A small change in pH number is a large change in concentration of the hydrogen ion. What seems like a small numerical change is actually a large change. Don't be fooled. A pH change of 0.10 pH units is significant to a marine fish that has never known the pH of its home waters to change by more than 0.01 units over the period of a year!
c. Salinity sets up the way the fish's internal chemistries function. The fish's internal physiology is based upon the fish's environment and that environment is the water, how much salt is in that water, and how clean that water ultimately is with regards to its home water quality. A fish can handle a rather rapid lowering of salinity (specific gravity) but not an increase in salinity. If salinity drifts too low in the system, raise it slowly (no more than 0.002 sp. gr. units per day). The fish's internal chemistries need time to adjust to a change in salt concentration in the water.
 

dmschiff

Member
My reason for asking is because my tap water tests 0 nitrates at first, but a few days later shows 5-10. I started another post with this question. Confused??????
 

socal57che

Active Member

Originally Posted by coachKLM
http:///forum/post/2489513
and some tidbits...
Some interesting information and things to know:
a. A sudden drop in temperature as little as 2F in an hour can cause a marine fish mucous coating to sluff off or improperly function.
This causes the fish to become sensitive to infection and diseases it could otherwise fend off. This is the reason why fish who go through a drop in temperature suddenly become ill or infected. A small drop in temperature is significantly far worse than a small rise in temperature.
Just makes me think. What happens to the temp of a reef during a thunderstorm? Does the temp not drop drastically with cloud cover and cold freshwater being dumped into the sea. Just something I've always wondered about.
 

socal57che

Active Member
Originally Posted by dmschiff
http:///forum/post/2489524
My reason for asking is because my tap water tests 0 nitrates at first, but a few days later shows 5-10. I started another post with this question. Confused??????
Are you using tapwater for water changes and top offs?
And, have you tested your tap water for ammonia?
 
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