Help with salinity measuring

[Dennis Cartier]

Wow I completely believed them to, I figured a company like Hanna instruments would know what they are talking about but upon reading what you wrote about ethanol there isn’t even enough organics in our reef tanks to change the outcome of a refractometer, so meaning if they are both calibrated correctly they should technically read the same discounting there margin of error on the devices, so that leaves me with the question of witch one is right? My Milwaukee or my Hanna salinity pen? That question is difficult to answer though.

As they say, "A man with a clock knows the time. A man with 2 clocks is never sure."

I have tried all the salinity tools available. Hanna pen, Pin Point EC meter, Icecap salinity tester, Milwaukee Refractometer, manual refractometer, etc. , all of the ones on the market, literally all of them.

My biggest disappointment was the Hanna Pen. I was so pleased when they brought it out. I thought it's Hanna, it's going to be good. Not my unit unfortunately. I can never get it to calibrate and hold a calibration. Super disappointed in that thing.

As I mentioned above, I use the TM High Precision floating hydrometers as they are the gold standard. I also scoured Ebay to hunt down some used Thermo Scientific conductivity meters. I got the idea to use the Thermo's from Randy. Those work wonderful, IF, you can find the right probe for the model you have, in the right measurement range, that still works (used). Finding working probes used is the key as they are crazy expensive new.

I have an Orion Star 3 that I use as my main meter, and a Orion 105A+ as my cross reference. The Star 3 gives a result in about 10 seconds after power on. The 105A+ takes about a minute to settle. By comparing the 2, I can tell that they are still in calibration ... or they both drifted equally

For calibrating the Orion's, I use a TM hydrometer as it does not require calibration.

NOTE: For the TM hydrometers, be careful where you source them. The ones sold in Germany do NOT measure in Specific Gravity (S.G), but instead measure in density. The readings look similar, but are not. Bad things will happen if you mistake the one for the other ... speaking for ahhh, friend.

Dennis

 

[IslandLifeReef]

I usually have my tank at 10 Alk but after my last water change I think it was too high in salinity and it boosted all my parameters. I’ve been letting them creep back down to minimize stress on the corals. Ideally I would like my Alk to be 10, Calc 450 Mag 1350 and ph 8.3 but idk how accurate my Hannah ph probe is I always calibrate it before checking so ‍♂. I can keep everything stable as long as my equipment is accurate

First, if you are calibrating your Milwaukee salinity tester, I would go with that. You are looking for consistency, not necessarily accuracy. If you are measuring 1.028 and the water is really 1.027, as long as it is consistent, I don't think you need to be worried by it. Oceans vary in salinity all across the globe and still manage to sustain the same life we are trying to keep.

As far as your tank parameters being stable goes, your PO4 seems really high. If that is fluctuating by 0.1 on a regular basis as you stated, that isn't stable. Same goes with ALK. If you are keeping your tank at 75 degrees, you may want to increase that a bit, you are hovering around the lower end of reef temps and not giving yourself a lot of room for error. Try making small changes over time.

 

[arking_mark]

Your issue is a shrunken losing color RBTA and your parameters look fine...maybe slightly higher salinity.

If the issue is water quality then several larger water changes with a quality salt may help the situation (never hurts).

Since RBTAs typically move to appropriate lighting and flow they prefer, I'd look at nutrition next and ensure it's getting fed.

As you bought a mature tank and I'm assuming the lights with it, it could be a bulb / lighting issues. Even LEDs have a effective life span...