Salinity

BRS
Jump to Last
shakinghorizons

shakinghorizons

Active Member
View Badges
Joined
Jul 13, 2016
Messages
395
Reaction score
108
Location
Denver, CO
Rating - 0%
0   0   0
I've been using a Pinpoint salinity monitor since I set up my tank and it consistently reads right around 35ppt. Well, I grabbed a couple clowns last week and everything was going fine until I added some turbo snails 3 days ago. I purchased 5 and 4 never moved after acclimating, 1 is still alive but moving slow (even for a snail). I decided to break out the refractometer and just compare the numbers. I calibrated the refractometer with some 35ppt fluid and the tank read 25ppt!! I grabbed more fluid and checked the Pinpoint monitor and it was at 48.7ppt! I put the probe in some rodi water and it read 1.7ppt, where the refractometer was reading 0.

I'm blown away at this point. I can't believe the clowns are still alive at such a low salinity! I have a couple zoa's in the tank and they were all open today and showing great color - how is that possible??

I plan to bring the salinity up over the next few days, but the current signs from the tank is that nothing is stressed. Any thoughts or help?

Disclaimer - the calibration solution is at least 4 years old and I've ordered more, which should be here this week.
 
I’d get an independent test to confirm. If it is low, bring it up slowly. I’ve always put salt water in my ato when I need to raise it. That brings it up very gradually.
 
shakinghorizons said:
I've been using a Pinpoint salinity monitor since I set up my tank and it consistently reads right around 35ppt. Well, I grabbed a couple clowns last week and everything was going fine until I added some turbo snails 3 days ago. I purchased 5 and 4 never moved after acclimating, 1 is still alive but moving slow (even for a snail). I decided to break out the refractometer and just compare the numbers. I calibrated the refractometer with some 35ppt fluid and the tank read 25ppt!! I grabbed more fluid and checked the Pinpoint monitor and it was at 48.7ppt! I put the probe in some rodi water and it read 1.7ppt, where the refractometer was reading 0.

I'm blown away at this point. I can't believe the clowns are still alive at such a low salinity! I have a couple zoa's in the tank and they were all open today and showing great color - how is that possible??

I plan to bring the salinity up over the next few days, but the current signs from the tank is that nothing is stressed. Any thoughts or help?

Disclaimer - the calibration solution is at least 4 years old and I've ordered more, which should be here this week.
Click to expand...

Ouch. Glad the clowns are okay. You could think of it as running a hyposalinity for a bit which is about what you have/had. Are you just going to do top offs with saltwater to slowly raise back up?
 
www.dinkinsaquaticgardens.com
The plan is to bring up the salinity through ATO.

But why would my zoa's but open and not showing signs of stress?
 
What does the Pinpoint read in air?

I've never heard of a conductivity meter that didn't read 0 in 0 conductivity water, and I'm not sure how it could.

I would warn to be very careful to not assume the refractometer is the correct one. Your only basis for thinking so is the standard, and if that is off, you may do harm rather than good changing the tank salinity.

If you calibrate the refractometer in RO/DI, then read the tank, what do you get?
 
What Randy said. I would not do anything until you can confirm there's a problem. You're treating a 4 year old salinity standard as your source of truth. Many factors could cause a salinity standard this old to be wrong. Why should either reading you're getting be any more correct than the other? You're using two completely different methods of measuring salinity and both could be wrong.

Personally, I would whip up a quick conductivity standard with some table salt and water. You can have this mixed up in under 10 minutes and know for sure if the conductivity meter is off. If you have a kitchen scale, measure out 2,149g of purified water. Mix in 73 grams of table salt. See what the conductivity meter say.
 
www.dinkinsaquaticgardens.com
Randy Holmes-Farley said:
What does the Pinpoint read in air?

I've never heard of a conductivity meter that didn't read 0 in 0 conductivity water, and I'm not sure how it could.

I would warn to be very careful to not assume the refractometer is the correct one. Your only basis for thinking so is the standard, and if that is off, you may do harm rather than good changing the tank salinity.

If you calibrate the refractometer in RO/DI, then read the tank, what do you get?
Click to expand...

Pinpoint reads 0 in air and 1.0 in rodi.
Calibrate 0 with rodi water in the refractometer, I get a reading of 25ppt of tank water
 
shakinghorizons said:
Pinpoint reads 0 in air and 1.0 in rodi.
Calibrate 0 with rodi water in the refractometer, I get a reading of 25ppt of tank water
Click to expand...

FWIW, the RO/DI water may not be 0 ppm TDS. It should match the reading in air when using a device like the Pinpoint. :)
 
Deltec
AS
Yeah, never ever assume a piece of testing equipment is accurate. As an example, I'm a diabetic. There have been times I've got low or high sugar readings on my glucose meter. Unless there is a corresponding feeling of illness or feeling faint that goes along with the reading, I always double check the result. Even if I'm not feeling well, I'll double check the result. Often times with another meter. You would be surprise how often I've had a bad test strip, or I didn't get all the water or alcohol off my hands before testing. That, and sometimes machines just either wear out, or have a manufacturing defect.
Just because your turbos are acting up doesn't and your test is showing to be off doesn't mean it's time to panic. It doesn't mean there's not a problem. It means you have two pieces of a puzzle to put together, and you need to figure it out. Looks like you have some people here willing to guide you through it though. Good luck!
 
Following up on this. I took some water to a couple LFS's today and determined that my calibrated refractometer is correct, so I'll be slowly increasing the salinity over the next week!
 
BRS

IF YOU HAD TO TAKE A REEFING EXAM, WOULD YOU PASS?

  • Yes!

    Votes: 32 45.7%

  • Not yet, but I have one that I want to buy in mind!

    Votes: 9 12.9%

  • No.

    Votes: 26 37.1%

  • Other (please explain).

    Votes: 3 4.3%
See comments…

New Posts

World Wide Corals
TCK Corals
Nutramar Foods
Top Shelf Aquatics
Tidal Gardens
Dinkins Aquatic Gardens
Deltec
Chewy.com
New Posts
Back
Top