Pinpoint Salinity Monitor

[bckane]

Ok Had to have some new toys.....Bought a Pinpoint Salinity Monitor, used the calibration fluid 53.0 mS. When I checked the water in my tank it was only 47.6 looking at the chart thats 1.0229...could my refract be off that far.????? I always set my mixed water to 1.0260 35.0 ppt

How accurate is the Pinpoint Salinity Monitor.? Should I calibrate it again.? Has anyone every had problems with this monitor.?

Brian

 

[jeffbrig]

Brian, I found the exact same thing when I got my pinpoint, my refractometer was way low (of course, that's why I bought the pinpoint). Assuming the calibration fluid is good, the conductivity based salinity meter should be extremely accurate.

 

[cayars]

Yep, sure could be especially if you calibrated it with RO/DI water. This is one of the reasons I'm not a fan of refractometers because it they aren't calibrated near the "target zone" they can be way, way off. I prefer a good floating hydrometer for most people unless you do things like hypo or have corals that require extreamly good/accurate salinity levels.

In those cases the Pinpoint Salinity Monitor is the way to go for the money. If you calibrate with the fluid it comes with you will be set and it will be very accurate for salt water aquariums.

Yes, absolutely check it against the calibration fluid again "just to make sure" but I'm sure it will read the calibration fluid accurately if you just calibrated it (doesn't hurt to check). Like many people you adjusted your tank salt water wrongly because of the refractometer and now need to adjust the water to the proper level.

To bring your salt level up to 35 ppt, do it very slowly. The best way to do this so you don't shock your system is to replace evaporated water with a stronger mixture of salt water. You want to make sure you only adjust specific gravity at a rate of 0.001 a day at most. You must go slow.

You can do a little math to figure out how to mix your new salt. For example if your total water volume is 75 gallons and lets assume you evaporate 1 gallon a day (substitue your own values).

75 gallons minus one gallon (evap) at 1.0229=74*1.0229=75.6946

1 gallon replacement water at 1.03=1*1.03=1.03

75.6946+1.03=1.022994667 specific gravity after first day.
((74*1.0229)+(1*1.03))/75

You can use that formula above to play and figure out your mixed up solution salt strength to use to replace evaporated water. Keep the daily change in specific gravity to 0.001 and you'll be on your way. If you can drip this solution that would be even better.

If you need to drip Kalk to keep alk/ph/calc up then you could always setup a second drip with the salt water and manually remove a gallon of water a day. You should have enough idea by now to figure out the best way to handle this for your tank but keep the salinity change slow or you'll be far worse then just leaving it at the low setting.

 

[newreefbishop]

I HATE MATH....lol

 

[bckane]

<a href=showthread.php?s=&postid=8621034#post8621034 target=_blank>Originally posted</a> by jeffbrig
Brian, I found the exact same thing when I got my pinpoint, my refractometer was way low (of course, that's why I bought the pinpoint). Assuming the calibration fluid is good, the conductivity based salinity meter should be extremely accurate.

Cool Thanks Jeff

 

[bckane]

<a href=showthread.php?s=&postid=8621421#post8621421 target=_blank>Originally posted</a> by newreefbishop
I HATE MATH....lol

I was never good in Math.......
But I will sure bring my Salt up slow....I cant believe it was off that Far
Brian

 

[bckane]

I do about a 10 gallon water change per week......what if I do a 1 gallon water change per day with my new salt mixture (35.0 ppt) for the next 10 days......that wait a week and do my normal water change.?
Brian

 

[ek9vboi]

Hey Brain be sure to bring your water into a few respectable LFS to get the salinity checked before you go whats based off the Pinpoint unit. I need to do that myself.

 

[bckane]

<a href=showthread.php?s=&postid=8621591#post8621591 target=_blank>Originally posted</a> by ek9vboi
Hey Brain be sure to bring your water into a few respectable LFS to get the salinity checked before you go whats based off the Pinpoint unit. I need to do that myself.

Maybe a good idea...but I bought 2 bottles of calibration fluid with my pinpoint monitor.....I checked the meter with both bottles of fluid and both came out to 53.0......if I dont trust the meter what will I trust....Ive always trusted my refractometer and always thought I was mixing my saltwater correct...but now Im having second thoughts

 

[ek9vboi]

If there isn't any really ill effects, then I wouldn't go off changing it too quick.

 

[jeffbrig]

I brought mine up from ~1.022 to 1.026 (53uS) in a little over a week. I mixed up a batch of saltwater to 1.035, and added about a gallon to the sump each day, just enough to keep my auto topoff from feeding freshwater. Over the course of a week, salinity rose gradually with evaporation, until I hit 1.026. I didn't see any signs of stress from my corals using this method.