new water to a cycling tank????

misty927

Member
Is it safe(recommended) to add new salt water to a tank that is almost done cycling. I have a 55 gal. that is almost done cycling with 45lbs.live rock, PC's, and CC. The tank needs about five gallons of water and I don't want to mess up the cycle. What should I do? :rolleyes:
 

coop21

Member
Is the five gallons from evaporation? If so, then just add some R/O water to your tank. Shouldn't hurt anything.
 

coop21

Member
Then you're ok to add R/O water to fill it back up. Just be sure not to add any salt, just water. Good luck!!!
 

misty927

Member
Dont we need to maintain our salinaty levels at the same time? Won't the salinaty decrease with an addition of five gallons of plain R/O water? Thank you for the help. ;)
 

coop21

Member
You're right. Five gallons of plain water seems like a lot, but just keep track of the salinity as you're doing it. Keep us posted.
 

dseiler

Member
Originally posted by misty927:
<STRONG>Dont we need to maintain our salinaty levels at the same time? Won't the salinaty decrease with an addition of five gallons of plain R/O water? Thank you for the help. ;)</STRONG>
Your salinity will decrease from where it is now, but only H2O evaporates so your salinity is actually higher now then when your tank was full. So by adding just water you will be making the salinity what it was before you had any evaporation.
Make sense?
HTH
[ May 04, 2001: Message edited by: Dseiler ]
 

misty927

Member
Dseiler, it all makes sense until you lift up the hood and find salt crystals on the glass from where the water evaporated or bounce up from the filter. :) But what i would still like to know is what will happen to my cycling tank if I add more water with salt mixed into it? :rolleyes:
 

dseiler

Member
Originally posted by misty927:
<STRONG>Dseiler, it all makes sense until you lift up the hood and find salt crystals on the glass from where the water evaporated or bounce up from the filter. :) But what i would still like to know is what will happen to my cycling tank if I add more water with salt mixed into it? :rolleyes:</STRONG>

The "salt creep" should have almost no effect on the salinity. Mind you I didn't say no effect, but almost none. So if you just add water your salinity levels will be fine. If you add saltwater your salinity levels will be raised, possibly too much.
As far as what will happen if you add water to your tank, it will be full again. Just kidding! :D :D Seriously, there will be no adverse effects by adding the water.
Your tank set up is similar to mine, except I have a ton more live rock, what are you going to put in it?
AHHH the legal drug known as salt water aquariums. :p
 

nm reef

Active Member
Misty....when I cycled my 1st I had the same question..........for evaporation add water(I use ro) to replace lost water.....salt does not evaporate so your salinity should stay constant.......adding top off should have no effect on your cycle
when doing water changes(remove water and replace) then you want to have the new water the same salinity as you keep your tank.......this replaces the salt you removed
Its my understanding that you should not change water until the cycle is complete...........it tends to prolong the cycle if you do so
If you add salt to your top-off water as you are asking it will adjust your salinity UP..........I guess you can if you intend to raise your salinity......hope this answered your question
 
K

krustytheclownfish

Guest
Just in case your question hasn't been answered, I'd fill up the aquarium. You have to do it sometime. I top mine off everyday(without salt). Whether you add salt to your fill-up water or not depends on what you want do to with the salinity. Keep in the range of 21-24. You should keep it at this even during cycling. Hope that helped.
 
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