Why wait to add new water?

[Kal]

I have just prepared water for a water change on my tank. The temperature and salinity line up (salinity is actually .001 lower to bring it down a bit). From what I understand I need to let this new water sit in the container with the power head on for some time. I was actually told at least 24 hours by my LFS. Is there a reason for this? Can I not just do the water change now?

 

[Dennis McGrath]

Gives it time for the salt to fully dissolve, as well as the PH to level out. You should check the SG and temperature before adding it to your tank to make sure all is well

 

[mta_morrow]

If the water is clear (salt dissolved), salinity and temp match, IMO you are good to go.

 

[Kal]

Thanks for the responses! I'll give it a few hours to make sure the water is fully clear and check salinity, temp, and PH

 

[chipmunkofdoom2]

The only real reason I know of for letting water sit is to allow for pH to equalize. Some salt manufacturers may balance the ingredients in their salt mix to produce a relatively high pH upon mixing. The pH will eventually trend down (assuming your home is like most and is rich in CO2) and will likely settle around your tank's pH. It just takes time for CO2 to dissolve in the new water and for the carbonate/bicarbonate/carbonic acid balance to shift into equilibrium.

Having said that, letting water sit for this reason isn't even necessary. At most, in the above case your tank's pH might increase a little bit, but that's about it. Sodium carbonate and calcium hydroxide additives also increase pH by a small amount with no ill effects (provided they are not overdosed). I don't even match the temperature of my water changes (although I do keep my water inside, so at most, it's only off by 10*F from tank temperature). As long as salinity matches and the water is clear, I use it regardless of how long it's been mixing.

 

[lapin]

From what I understand I need to let this new water sit in the container with the power head on for some time. I was actually told at least 24 hours by my LFS.

Good Question.....Each salt mix is different. Follow the directions from the manufacture for the best results.

 

[don_chuwish]

I go from a couple of hours and 'looks good to me' to days if I can't quite find the time to do the change right after mixing. Typical is overnight though. Only bother heating it in winter after fully mixed. No need to heat with warmer weather.

 

[Potatohead]

As stated above I would follow manufacturer recommendation. However if you are in a time crunch, the water is clear, salinity/temp/ph are all in line, I have done changes like that in the past without any problems.

 

[Kal]

So the water took through the night to clear up. I guess if that's the baseline I have my answer! Thanks all!

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, I would not overly rely on manufacturer claims about how to mix a salt. I don't think they know anything we don't, and sometimes the recommendations do not even make sense, and in at least one case, it is technically impossible to follow.