question on the salinity...

[carpenter981]

Im wondering if this is nomal...

Ive got a 60 gallon display with a 20 gallon sump (65-70 gallons total). I did my usual 20% water change last week with water at a salinity of 1.023. I again did my usual water change yesterday with 1.023 again. I checked the water params today and the salinity is at 1.027.

I didnt check it before I did a water change yesterday, so is it normal to have the salinity jump that high in a week? I top it off during the week with the normal 1.023

Im using a cheap hydrometer but its pretty consistent on any water that I check.

any ideas?

 

[rbredding]

you top off with new salt water? (that's not supposed to happen)



topoff should be done with pure water only... (no salt)

you're replacing the water that evaporates off your system (when the water evaporates, it leaves it's mineral content behind, thus raising the concentration of salt) you topoff fresh water to bring the salinity back down (by diluting the given minerals over a larger quantity of system water)

 

[carpenter981]

Rbredding;589396 wrote: you top off with new salt water? (that's not supposed to happen)



topoff should be done with pure water only... (no salt)

you're replacing the water that evaporates off your system (when the water evaporates, it leaves it's mineral content behind, thus raising the concentration of salt) you topoff fresh water to bring the salinity back down (by diluting the given minerals over a larger quantity of system water)

yeah, I guess thats my mistake. I figured you just topped off with fresh salt water. Ill start doing that this week then.

Thanks

 

[rbredding]

no problem... (you might want to drain some off now and replace it with fresh water so you can lower your salinity)

 

[jennm]

Water evaporates. Salt does not. So if you top off with saltwater, over time the specific gravity will increase. Replace your evaporated water with fresh RO/DI, and when you do a water change, of course, replace the saltwater you removed, with new saltwater.

Also, if your system is low on water (due to evap) before you start a water change, take that into consideration too... either top it off before you change water, or factor that in when mixing new saltwater (ie make it a bit less than your target specific gravity).

Jenn

 

[carpenter981]

thanks guys. That all makes perfect sense, it just never crossed my mind. I added some fresh in it and brought it down to 1.025.

a refractometer is definitely on my wish list for when Im not broke...