Help!, salinity too high

[fish_collector]

I use an Amazon salinity refractometer, just last weekend I had it at a fellow hobbyists house checking it against the methods he uses and it agreed with everything we compared it to. Primarily he has a Milwaukee salinity meter and fresh calibration fluid, and my unit was spot on with it.

To be quite honest it’s not that important. Just somewhere in the ballpark is fine for even acros, and for fish it’s even less critical. I have an old school swing arm that I compare to sometimes, it’s not adjustable and tells the truth. As long as my refract agrees with the swing arm I’m good.

Unless a refractometer has a sloppy adjusting screw or the lens is loose or something obvious going on with it, it should never need continuous recalibration. I may even go so far as to say just use it the way it came out of the box and don’t give it too much thought. It truly is not that critical, 1.024, 1.025, halfway between 34 and 35 ppt makes no difference. I let my ATO go empty because well, I’m lazy and didn’t make time to refill it, I’d been watching my return pump chamber go lower and lower until it finally let a pump suck air. When I tested the salinity it was 1.029 so I added almost 4g of RODI all at once. It causes zero problems with the fish or the dozens of acros that are in the tank. Is it right to do that? No, but it’s something that has little effect on things, in my tanks anyways. So perhaps we overthink exact salinity measurements?

 

[TCOTU]

Thanks to everyone who chimed in. My main question has to do with reef chemistry, as to whether dosing two parts could cause quick salinity rise if I mixed the chemicals incorrectly. Sounds like the answer to that was no. As for accuracy of testing device, I think as long as one uses same methods every time, it should be fine. It's the trend that matters, not the absolute number. Like someone said above, this is a rabbit hole that one can fall into, trying to figure out the cause. So far I have not find the definitive culprit. I guess going forward, I just need to religiously test salinity and add more RODI if it start to rise again. Speaking of testing, how many here use salinity probe to constantly keep track of it? Personally I find using refractometer easy enough. But perhaps automating yet another step will finally make me a better reefer, (or a more lazy one.)

 

[mcarroll]

I wonder if your ATO has saltwater in it by mistake? That would do it.

How are you measuring your Tropic Marin when you mix up a batch? How much powder are you adding to how much water?

 

[TCOTU]

I wonder if your ATO has saltwater in it by mistake? That would do it.

How are you measuring your Tropic Marin when you mix up a batch? How much powder are you adding to how much water?

I did measure my ATO water as well. It was not salt water. I have a water mixing station where I transfer 20 G of RODI water to the saltwater tank, add 10 cups of tropic marin salt and use circulating pump as well as pump in the tank to stir. The water that result has salinity of 1.024. This has been my routine for 5 years and nothing was changed recently. I had wondered if my mixing was incomplete, where salt settles down near the bottom while I usually take water from the top of the tank to test. But this is not the case. I tested water from the bottom of the tank as well as from the line where it goes into my sump. Both are at 1.024. I have eliminated ATO, auto water change and now two part dosing as culprit. I don't know where else could the extra salt be coming from.

 

[mcarroll]

Thanks to everyone who chimed in. My main question has to do with reef chemistry, as to whether dosing two parts could cause quick salinity rise if I mixed the chemicals incorrectly. Sounds like the answer to that was no. As for accuracy of testing device, I think as long as one uses same methods every time, it should be fine. It's the trend that matters, not the absolute number. Like someone said above, this is a rabbit hole that one can fall into, trying to figure out the cause. So far I have not find the definitive culprit. I guess going forward, I just need to religiously test salinity and add more RODI if it start to rise again. Speaking of testing, how many here use salinity probe to constantly keep track of it? Personally I find using refractometer easy enough. But perhaps automating yet another step will finally make me a better reefer, (or a more lazy one.)

Salinity probes seem to be the most upkeep and least reliable of any testing method....the increased accuracy makes those activities "worth it" only in some cases where the accuracy is actually needed.

Most of us do not need that kind of accuracy for almost anything....fish and corals are adapted to the ocean, which DOES NOT have a steady salinity. So minor variances "from spec" hurt nothing.

An exceptional situation is hyposalinity for disease control....the salinity level has to be so low in order to be effective vs disease that if it were any lower it would harm the fish. So a more accurate salinity tester *might be* required in that case....maybe making the upkeep of a salinity meter worthwhile in that case. (A refractometer is still perfect too – very accurate and very precise.)

As long as your refractometer reads "0" when you test RODI water (probably for tap water too) then it's probably fine. RODI is a fine calibration check....and even as a primary calibration standard it could only cause insignificant variance "from spec" for daily use. Make sure you look at the article @Jay Hemdal wrote on the topic....much more even-keeled than all the threads on the topic lately. (Thanks for that, Jay!)

 

[Jay Hemdal]

Salinity probes seem to be the most upkeep and least reliable of any testing method....the increased accuracy makes those activities "worth it" only in some cases where the accuracy is actually needed.

Most of us do not need that kind of accuracy for almost anything....fish and corals are adapted to the ocean, which DOES NOT have a steady salinity. So minor variances "from spec" hurt nothing.

An exceptional situation is hyposalinity for disease control....the salinity level has to be so low in order to be effective vs disease that if it were any lower it would harm the fish. So a more accurate salinity tester *might be* required in that case....maybe making the upkeep of a salinity meter worthwhile in that case. (A refractometer is still perfect too – very accurate and very precise.)

As long as your refractometer reads "0" when you test RODI water (probably for tap water too) then it's probably fine. RODI is a fine calibration check....and even as a primary calibration standard it could only cause insignificant variance "from spec" for daily use. Make sure you look at the article @Jay Hemdal wrote on the topic....much more even-keeled than all the threads on the topic lately. (Thanks for that, Jay!)

Yeah - I had like 20 different meters, refracts and hydrometers at work and my staff all had their favorites, but there was a LOT of variation, like the Tower of Babel. I wrote this article to try and get them all on board and speaking the same language:

Measuring Salinity / Specific Gravity in Aquariums

This article gives an overview of measuring specific gravity / salinity in aquariums.

www.reef2reef.com

 

[Randy Holmes-Farley]

Thanks to everyone who chimed in. My main question has to do with reef chemistry, as to whether dosing two parts could cause quick salinity rise if I mixed the chemicals incorrectly. Sounds like the answer to that was no. As for accuracy of testing device, I think as long as one uses same methods every time, it should be fine. It's the trend that matters, not the absolute number. Like someone said above, this is a rabbit hole that one can fall into, trying to figure out the cause. So far I have not find the definitive culprit. I guess going forward, I just need to religiously test salinity and add more RODI if it start to rise again. Speaking of testing, how many here use salinity probe to constantly keep track of it? Personally I find using refractometer easy enough. But perhaps automating yet another step will finally make me a better reefer, (or a more lazy one.)

I think I answered that absolutely. No.

 

[mcarroll]

I transfer 20 G of RODI water to the saltwater tank, add 10 cups of tropic marin salt

Seems like that ought to be asa right as you need it to be.

Did you already mention that you gave your testing device a sanity check by measuring something different like tap water to see if it gives you the expected answer in a different scenario?

Otherwise it seems like you have yourself a mystery!