Salinity levels...too high?

[DarthReefer27]

I have had my 29 G biocube mixed reef up for just over 6 months and everything is doing well (except that i cannot seem to keep shrimp other than peppermints alive). i mix my own salt water using red sea coral pro and using my pinpoint salinity monitor in my salt bucket, i mix it to pinpoint's measurement of 53 which is 35 ppt or 1.026 sg. however, my apex salinity probe is constantly showing 37-39 ppt. i assumed that was just off since everything was fine and the pinpoint monitor after mixing salt was always at 35 ppt. i purchased a refractometer to check and my tank is close to 40 ppt. so three questions: first, i guess when i mix up 10 gallons of salt water and then put 3 gallons into the tank, could those 3 gallons could be higher? is that possible? second question is how do i get it lower and then lastly, is 40 ppt high enough to kill off inverts such as cleaner shrimp? all my fish are doing fine and my corals are also all doing fine. i did also just find out my nitrates are very high so i must need to do some deep cleaning (i found there is a lot of gunk at the bottom of the back chambers of the biocube. my guess is that is causing some of the high levels.

 

[shifty51008]

40ppt is very high and could be a good reason inverts are dying, fish and corals ime can handle different salinities better.

How did you calibrate the refractometer?

 

[downbeach]

Along with your refractometer, are the other devices calibrated, clear of any interference?
https://www.youtube.com/watch?v=NyC8x57E5DA
https://www.youtube.com/watch?v=l0-D9Q2sMis

 

[Luke Schnabel]

to lower your salinity wouldn't you just take some water out and replace it with RODI water? that should lower the salt content.

 

[Shawn O]

to lower your salinity wouldn't you just take some water out and replace it with RODI water? that should lower the salt content.

+1

Remove one gallon and replace with straight RODI, slowly. That is, if your water is too high in salinity. Determine which testing equipment is in error and replace or recalibrate it.

 

[Fallling]

Make sure you refractometer is calibrated. If it is 40ppt, that's high. As long as the newly mixed saltwater is mixed thoroughly, then is should be a consistent salinity. Lower it slowly with either straight RODI water or water with a lower salinity. I'd say lower it down to 35ppt over 4 - 5 days. Also, make sure when you top off, you use RODI water and not salt water.

 

[DarthReefer27]

Make sure you refractometer is calibrated. If it is 40ppt, that's high. As long as the newly mixed saltwater is mixed thoroughly, then is should be a consistent salinity. Lower it slowly with either straight RODI water or water with a lower salinity. I'd say lower it down to 35ppt over 4 - 5 days. Also, make sure when you top off, you use RODI water and not salt water.

I have found that reading the red sea refractometer is rather difficult, especially since I wear glasses. However, i did calibrate my neptune probe correctly so I am going to assume it is correct. I will try the daily removal of water and addition of RODI until it reaches 35. my ATO (of course with RODI) will keep it filling up as i remove the tank water daily. thanks for the advise.

 

[Kobashi]

About 2 years ago, I set up a friend with a 14g saltwater tank. I took the time to explain all the basics, checked up on him (and the tank) pretty good for 6 months. He read up on it and learned a lot about doing it successfully and decides to purchase pre-mixed (1.024) water from the LFS.

Mostly a swim tank, he did get corals from time, which typically melted away in a month or two. It was a small tank, but he religiously took a 32oz cup of water out (and put 32oz of salt water back in) 3-4x a week since it did not have a skimmer (and because it was a nano).

Skip ahead... 2 years later, he gets a little frustrated with not being able to keep inverts or (easy) corals. I take my equipment over... his clownfish are lethargic and his water is at 1.033. He's astonished since the LFS's water is 1.024... but he never learned (I know I told him) to "top off" with plain RODI water.

Anyway... the lesson is... quadruple check everything and assume nothing. For instance, I would think that he would know this from reading, learning it from my instructions (but to his defense, I'm sure he was "swimming" with information in the first few weeks), from the LFS he goes into every other week (to buy water), basic intuition (he has a college degree in biology funny enough), or even on RC (he reads things here every now and then).

I would have someone bring their refractometer over (and other equip), or take yours over to a friends and make sure your readings are the same... or just buy the $1.99 "calibrating liquid" (to zero it out). Or take it to a LFS store and compare side by side too.

Here's a couple of other quick things (again, sorry if I'm insulting you... just another check).
- Are you mixing the water COMPLETELY for at LEAST 1 hour before putting it in the tank? The recommendation is overnight... but I get it, we don't always have 2 time slots to mess with the tank... I always mix to 1.022-1.023, add the new water to the sump (furthest chamber from the return pump just in case undissolved crystals need a little more time) if I'm doing it with the MINIMUM 1 hour method. (Sounds like (mixing 10g) you're kinda doing this... but that first batch might not be completely dissolved, and if you don't check a few days later, you might find your remaining water might be stronger).
- Adding RODI water will immediately bring down the salinity... it will be safe as long as you don't do it too fast. (One cup of saltwater out, one cup of RODI in... (a few hours in-between) over a couple of days replacing a gallon or two should do the trick)
- I would say that inverts are more "sensitive" than most corals to changes in water parameters.

Anyway, I hope this helps.