I have a 55gal tank with hob filter (no sump). I use a refractomer every morning faithfully to verify my salinity. Typically it runs between 1.0255 and 1.0265. Depending on where it is I add between 2-4 cups of top off ro/di water each day to maintain the salinity where I want it. This morning when I checked it my salinity was a whopping 1.028. Yesterday it was normal. I added water like normal to bring it down to 1.025 expecting a typical increase up to 1.026. No, I didn't forget. How does this happen?
Salinity Spike?
- Thread starter Foody
- Start date
Conesus_Kid
Premium Member
When was the last time you calibrated your refractometer? Make sure you're using calibration solution that's at 35 ppt (NOT distilled water).
Even though refractometers can be pricey, many of them are cheaply made and get knocked out of whack really easily.
Even though refractometers can be pricey, many of them are cheaply made and get knocked out of whack really easily.
EllieSuz
Premium Member
If you mark your tank in an inconspicuous place when your salinity is exactly where you want it, and you top-off to that mark every time, there should be no need to test your salinity so often. Remember, topping off is not to adjust salinity, but to maintain it. I have a piece of tape in my sump and I find that if I keep the water at that line, my salinity stays at 1.025, right where I want it. Now, after measuring it frequently at first to verify it, I only test it occasionally and just before and after a water change.
Refractometer is only 2 months old. It was calibrated with calibration solution. I keep it on the shelf next to my tank and it is handled CAREFULLY, knowing how easily they are knocked out. I took a water sample to the reef shoppe and verified mine against theirs. It's not the refractometer. I am absolutely certain that I had a 2-3 point spike on one night.
block head
New member
Refractometer is only as good as its calibration solution. Evaporation is a mofo. My brs cheap stays dead nuts. Had others that needed daily calibration. My nanos swing horribly at times
Gary Majchrzak
Team RC
solids in the water don't evaporate
solids in the water don't evaporate
there is absolutely no reason to be checking salinity every day.
Unless there's a leak and saltwater is escaping the system or you're skimming really wet- do NOT check S.G. every day to adjust it.
Add freshwater to replace evap. That's all.
solids in the water don't evaporate
there is absolutely no reason to be checking salinity every day.
Unless there's a leak and saltwater is escaping the system or you're skimming really wet- do NOT check S.G. every day to adjust it.
Add freshwater to replace evap. That's all.
block head
New member
2-3 is probably about right in dry winter conditions. I some times lose a gallon to evap. Not a big deal on 220s. On smaller tanks it can cause problems especially if you have other complications. It might be normal for your tank. Maybe something got bumped, or maybe the furnace is pulling a lot of h20 to heat your home. The actual salinity is what it is. I' m confident the swing is accurate. Watch and see what's normal. I wouldn't lose sleep over it .
