evaporation question
- Thread starter twogirls
- Start date
me-n-my-fish
Member
The salt will stay. only top off with fresh water.
azaintcold
Member
Originally Posted by twogirls
when your water evaporated, does the salt evaporate with it? I've seem to have heard that you need to be careful with water evaporation because your salinity can spike, but my tank never does that. When the tank gets low I add fresh ro water and then my sality gets too low. HELP
The salt doesn't evaporate with the fresh water. The only reason I can see your salinity changing is if you aren't filling to the same spot every time, or you have some seriously excessive salt creep. How big is the tank?
when your water evaporated, does the salt evaporate with it? I've seem to have heard that you need to be careful with water evaporation because your salinity can spike, but my tank never does that. When the tank gets low I add fresh ro water and then my sality gets too low. HELP
The salt doesn't evaporate with the fresh water. The only reason I can see your salinity changing is if you aren't filling to the same spot every time, or you have some seriously excessive salt creep. How big is the tank?
scsinet
Active Member
How much water is evaporating in between topoffs?
In theory, you should calibrate the salinity of your tank when the water is at a "full" condition. Ergo, when the tank is full, dial it in to 1.025. As water evaporates, that will slowly rise. If you lose say 5 gallons of water, that's only 7% of the total water volume, so in theory the salinity should be at 1.026-1.027, which is still acceptable.
If you are saying that your salinity goes UP with a topoff, then drops as water evaporates, you are almost certainly losing water to a leak somewhere, or your measuring device is inaccurate. If your tank is leaking, the saltwater is leaking out, so as you top off, your salinity is slowly declining over time because you are not replacing the salt that leaves with the leak. Of course, I find it hard to believe you wouldn't notice the water leaking...
If you are measuring with a cheap swing arm hydrometer, it could just be the margin of error of the device. If you measure during different times of the day when the water is differing temperatures, that too can throw you because the swing arm units are not ATC (automatic temperature compensating).
In theory, you should calibrate the salinity of your tank when the water is at a "full" condition. Ergo, when the tank is full, dial it in to 1.025. As water evaporates, that will slowly rise. If you lose say 5 gallons of water, that's only 7% of the total water volume, so in theory the salinity should be at 1.026-1.027, which is still acceptable.
If you are saying that your salinity goes UP with a topoff, then drops as water evaporates, you are almost certainly losing water to a leak somewhere, or your measuring device is inaccurate. If your tank is leaking, the saltwater is leaking out, so as you top off, your salinity is slowly declining over time because you are not replacing the salt that leaves with the leak. Of course, I find it hard to believe you wouldn't notice the water leaking...
If you are measuring with a cheap swing arm hydrometer, it could just be the margin of error of the device. If you measure during different times of the day when the water is differing temperatures, that too can throw you because the swing arm units are not ATC (automatic temperature compensating).
twogirls
Member
about a gallon or 2 between top offs. I try to top it off every day.
it doesn't go up with top off, it just gradually keeps going down. I'll get my tank set and it's fullest at 1.025-1.026 and within a week at it's fullest it will be at 1.023 or so.
No leaks, that would suck.
I have a refractometer so I don't think it's an error.
it doesn't go up with top off, it just gradually keeps going down. I'll get my tank set and it's fullest at 1.025-1.026 and within a week at it's fullest it will be at 1.023 or so.
No leaks, that would suck.
I have a refractometer so I don't think it's an error.
twogirls
Member
I do not have much salt creep. Almost none. It isn't always up to 2 gallons a day, sometimes I only top it off every other day. I have a 72 gallon tank and a 15 gallon sump. I'm not too stressed about the amount of evaporation, just the salt issue.
the tanks temp is at about 80 degrees at all time.
the tanks temp is at about 80 degrees at all time.
baloo6969
Member
odd. well as scsi said, salt just dosent disappear. one of 2 things, your either adding more water than is evaping or you have mad salt creep...is your skimmer out of wack? Maybe the gunk is having salt come with it...i know they only work in SW, unless you change the venturi...
me-n-my-fish
Member
Originally Posted by spanko
SCSInet, I only have a 29 gallon bio cube so it is covered and I don't have a problem with evaporation. But my question to you to help twogirls is does one or two gallons top off each day seem like a lot in a 72 gallon tank?
I have 1-2 gallons a day in my 110.
Salt has to be getting out somewhere. Only place i can see it is the skimmer. But thats a big diff in salt with just dumping skimate (sp).
No leaks, no super hugemongus salt creep....
I guess one starting point would be to verify your refractometer is reading correctly. Take some water, you test it, and have your LFS test it with a refractometer if they have one. Should be pretty close. If not, maybe your getting false readings?
SCSInet, I only have a 29 gallon bio cube so it is covered and I don't have a problem with evaporation. But my question to you to help twogirls is does one or two gallons top off each day seem like a lot in a 72 gallon tank?
I have 1-2 gallons a day in my 110.
Salt has to be getting out somewhere. Only place i can see it is the skimmer. But thats a big diff in salt with just dumping skimate (sp).
No leaks, no super hugemongus salt creep....
I guess one starting point would be to verify your refractometer is reading correctly. Take some water, you test it, and have your LFS test it with a refractometer if they have one. Should be pretty close. If not, maybe your getting false readings?
1journeyman
Active Member
Ok, that's a mystery to me.
I too tend to lean towards a leak, except by now you would have seen gallons of water on the floor.
Sounds like you are testing properly. Do this; test the salinity in both your sump and display. Is there a change? Could it be that you are adding FW to your sump and it is taking a while to get mixed into display?
Edit: Gonna ask the other mods to look in on this as well.
I too tend to lean towards a leak, except by now you would have seen gallons of water on the floor.
Sounds like you are testing properly. Do this; test the salinity in both your sump and display. Is there a change? Could it be that you are adding FW to your sump and it is taking a while to get mixed into display?
Edit: Gonna ask the other mods to look in on this as well.
twogirls
Member
Originally Posted by Katz
Twogirls, I am having the same problem as you are having and I have yet to figure it out either. In my other tank the Salt level always went up as water evaporated, but in this tank it always goes down after I add top off water.
I am glad that you posted this question.
And thank you, I don't feel like such an idiot just knowing that I am not the only one.
Twogirls, I am having the same problem as you are having and I have yet to figure it out either. In my other tank the Salt level always went up as water evaporated, but in this tank it always goes down after I add top off water.
I am glad that you posted this question.
And thank you, I don't feel like such an idiot just knowing that I am not the only one.