vb_reefs
Active Member
Hello everyone, I really tried to figure this out before making this thread. I also read a few similar threads from other members with similar problems. But decided to make my own thread in the end (hopefully this is in the correct area). I apologize in advance for the long read.
Tank is a Innovative Marine EXT 25g (used as a frag tank) plumbed into a Geo 36 sump. I had a 120g and the IM EXT tank plumbed together. But sold off the 120g for a upgrade. These past few days/week I've been chasing salinity. I've been using Brightwell NeoMarine salt for a few years now with not problems since day one. Salinity at 35ppt via Hanna - HI98319 Salinity checker since the begining. Calibrating once every other month with no problems. Here is where the issues started happening and I kind of wish I didn't look into it as much.
I sent a ICP test using ATI and received the results on 2/22/23. Salinity came back 36.99, no issues at all with corals (more LPS dominant) other then a few tester acros not looking the best but was still doing ok. After seeing the result I then went to verify the ATI results with my hanna checker, it still was spot on at 35ppt. I run a Apex as well, but I know how unreliable the salinity probe is. So I just use it as a reference for stability. Prior to making any changes, with hanna reading at 35pp, ATI results at 36.99, my Apex probe would register between 36ppt - 37ppt (best i can get it to read to 35ppt).
This is where the chasing salinity began and corals started to feel all the changes. I brought out the trusty ATC refractometer, I used a calibration solution from brightwell. I'm wondering if I can be using the wrong calibration for it as well. But it reads 35ppt when tested. Before making any changes, I checked salinity using the ATC refractometer. Salinity was reading close to 40 ppt - 41ppt. Yet, hanna was reading 35ppt and apex was reading on the higher side of 38ppt - 39ppt. I thought something is off because I'm getting readings all over the place. Calibrated the hanna, I even let the solution sit for a few hours before calibrating. Hanna checker calibrated and reading 35ppt while in solution. When placed into the tank, readings are now 34.1 ppt?! I read into several threads and even watch a youtube video (I think on WWC channel, not 100% sure) about a hobbyist that almost crashed his tank. He too used a hanna checker that was not reading salinity accurately despite being calibrated.
I started to lower salinity based of the refractometer and not the hanna (thinking it finally gave up as I've used it for a few years now). Interesting thing was that as my salinity got closer to 35ppt, my apex probe was actually correlating as well. Not spot on, but trended the same direction as the refractometer. On the other hand, I'm getting really low reading when using the hanna, registering at 33.1 - 33.4
Now looking to buy a Milwaukee refratometer just to see if i can rule out any instruments reading incorrectly. I'm looking to send in another ICP as well, but debating on which to use this time. ATI kinda takes a long time to get results back. I'd like to get the corals looking better before any die off happens. I do see some bleached tips on acros. My space invader is not swelled/puffed up like normal. Torches seems to be ok, but some hammers are not as open as well.
My next step is to make a "Randy's calibrations fluid" and test that with each refractometer. I could use any recommendations or advice others may have.
Tank is a Innovative Marine EXT 25g (used as a frag tank) plumbed into a Geo 36 sump. I had a 120g and the IM EXT tank plumbed together. But sold off the 120g for a upgrade. These past few days/week I've been chasing salinity. I've been using Brightwell NeoMarine salt for a few years now with not problems since day one. Salinity at 35ppt via Hanna - HI98319 Salinity checker since the begining. Calibrating once every other month with no problems. Here is where the issues started happening and I kind of wish I didn't look into it as much.
I sent a ICP test using ATI and received the results on 2/22/23. Salinity came back 36.99, no issues at all with corals (more LPS dominant) other then a few tester acros not looking the best but was still doing ok. After seeing the result I then went to verify the ATI results with my hanna checker, it still was spot on at 35ppt. I run a Apex as well, but I know how unreliable the salinity probe is. So I just use it as a reference for stability. Prior to making any changes, with hanna reading at 35pp, ATI results at 36.99, my Apex probe would register between 36ppt - 37ppt (best i can get it to read to 35ppt).
This is where the chasing salinity began and corals started to feel all the changes. I brought out the trusty ATC refractometer, I used a calibration solution from brightwell. I'm wondering if I can be using the wrong calibration for it as well. But it reads 35ppt when tested. Before making any changes, I checked salinity using the ATC refractometer. Salinity was reading close to 40 ppt - 41ppt. Yet, hanna was reading 35ppt and apex was reading on the higher side of 38ppt - 39ppt. I thought something is off because I'm getting readings all over the place. Calibrated the hanna, I even let the solution sit for a few hours before calibrating. Hanna checker calibrated and reading 35ppt while in solution. When placed into the tank, readings are now 34.1 ppt?! I read into several threads and even watch a youtube video (I think on WWC channel, not 100% sure) about a hobbyist that almost crashed his tank. He too used a hanna checker that was not reading salinity accurately despite being calibrated.
I started to lower salinity based of the refractometer and not the hanna (thinking it finally gave up as I've used it for a few years now). Interesting thing was that as my salinity got closer to 35ppt, my apex probe was actually correlating as well. Not spot on, but trended the same direction as the refractometer. On the other hand, I'm getting really low reading when using the hanna, registering at 33.1 - 33.4
Now looking to buy a Milwaukee refratometer just to see if i can rule out any instruments reading incorrectly. I'm looking to send in another ICP as well, but debating on which to use this time. ATI kinda takes a long time to get results back. I'd like to get the corals looking better before any die off happens. I do see some bleached tips on acros. My space invader is not swelled/puffed up like normal. Torches seems to be ok, but some hammers are not as open as well.
My next step is to make a "Randy's calibrations fluid" and test that with each refractometer. I could use any recommendations or advice others may have.
