RUH ROH! Salinity Issue (1.031 SG.. oops)

[ConnorD42]

So I should preface this with my tank is almost 2 years old now (will be as of mid-ish April) I have been using a hydrometer from Instant Ocean for the entire time I have been in the hobby. I just use instant ocean and dose to desired chemical levels, I know, I know- I'm in college. The new tank is using Red Sea reef salt (forgot the specific name sorry, black bucket from Red Sea).

 

Through this time after (almost) each use, I have rinsed the hydrometer out with fresh water really well so i didn't run into any issues. I figured this was good practice and would allow for more accurate readings. Whelp.. This Christmas I got my dad a small tank as a gift for looking after mine while I was on my co-op rotation a few states over. Just beginning since my tank and equipment were still home, we used my hydrometer to check his salinity; 1.019-1.020 SG for his tank, and my tank showed at 1.0265 SG. So he added more salt to his tank (more than what should have mixed 1.026 SG- should have been the first red flag to me, I realize this now).

 

The following day he purchased his own hydrometer which instantly pegged 1.032 SG when reading his tank's water. Yikes; I measured mine with the new meter- 1.032 SG. My own meter still read my water as 1.0265, and read dad's water at 1.023. Everything looked happy and healthy so I wasn't super concerned at the time and we figured it was just a funky meter. Well he bought a second one and it did the same thing (this should have been red flag #2).

 

Fast forward a few weeks and one move back into my apartment at school later, everything still happy and healthy looking! A couple corals started exhibiting some unusual behaviors that I've had for a while now. Nothing earth shattering, just a funny feeling that something might be up that I'm not seeing. I ran out today and bit the bullet and bought a refractometer to finally get my answer about my specific gravity. After a quick calibration and sample of tank water I about threw up- 1.031 SG!! I am in the process of slowly lowering the salinity back down to 1.025 SG as I type this. I really don't know how my hydrometer would have been thrown that out of kilt, but just a PSA for everyone using hydrometers that are about a year and a half old- check your equipment!! I'm just thankful that I didn't lose any of my fish or corals.

 

TL;DR- My instant ocean hydrometer crapped out on me, I bought a refractometer and my SG was 1.031! (everything still alive, phew)

Edited February 12, 2020 by ConnorD42
missing detail

[Steemax]

I'm a bit confused because you said your Hydrometer and your fathers new Hydro both read 1.032... then the refractometer also ready 1.031. So the Hydro's were correct no? Also did you "season" the new Hydro? It's recommended for accuracy. Usually it's on the package. 

 

 

[ConnorD42]

2 minutes ago, Steemax said:

I'm a bit confused because you said your Hydrometer and your fathers new Hydro both read 1.032... then the refractometer also ready 1.031. So the Hydro's were correct no? Also did you "season" the new Hydro? It's recommended for accuracy. Usually it's on the package. 

 

 

Mine was 1.023 my bad. I'll fix that now. His we did not, but mine I did when I got it. 

[Steemax]

Just now, ConnorD42 said:

Mine was 1.023 my bad. I'll fix that now. His we did not, but mine I did when I got it. 

Gotcha, that makes more sense now... I'm glad you didn't lose any fish or coral at least. One more thing to consider though. Mine would instantly peg the top if there are any tiny bubbles on the swing arm so i'd have to flick the hydro to break those loose. 

[ConnorD42]

8 minutes ago, Steemax said:

I'm a bit confused because you said your Hydrometer and your fathers new Hydro both read 1.032... then the refractometer also ready 1.031. So the Hydro's were correct no? Also did you "season" the new Hydro? It's recommended for accuracy. Usually it's on the package. 

 

 

I had to reread that bit, I left out a tiny detail and I think I answered your question wrong initially.

 

The new meters were reading very high, and my meter was reading insanely low. The new meters read 1.032 for both tanks both times until dad was able to change and cycle enough water through the tank to bring the salinity back down, thus showing up correctly a few days later (or more correctly than mine to the point). Mine read his tank at 1.023 while his meter said his tank was 1.032 or higher, and his meter read my tank at 1.032 or higher while mine read my tank at 1.026. The more I read, think, and reread, the less and less it makes sense. I can only imagine how this sounds to someone trying to make any sense of it lol.

[ConnorD42]

5 minutes ago, Steemax said:

Gotcha, that makes more sense now... I'm glad you didn't lose any fish or coral at least. One more thing to consider though. Mine would instantly peg the top if there are any tiny bubbles on the swing arm so i'd have to flick the hydro to break those loose. 

Yeah I have only noticed bubbles in mine a handful of times, and typically would take a reading 3 or 4 times just to be sure and it almost always read the same thing. But same! Approaching normal levels again. Glad I had to come down and not up I guess since that's a lot easier on the fish.

[Garf]

How slowly are you bringing it down? And are you dosing anything? It may be better to monitor dkh, and bring that down slowly instead of relying on salinity as your measure. Or basically, mix your saltwater at your desired levels and figure out a % based reduction based on estimated volume. so probably smaller water changes over a period of time.

 

 

[ConnorD42]

On 2/12/2020 at 8:13 PM, Garf said:

How slowly are you bringing it down? And are you dosing anything? It may be better to monitor dkh, and bring that down slowly instead of relying on salinity as your measure. Or basically, mix your saltwater at your desired levels and figure out a % based reduction based on estimated volume. so probably smaller water changes over a period of time.

 

 

I ended up bringing it down about 0.001 SG every hour to hour and a half since it's easier on the fish going down the gradient than up. I am dosing Ca, alk, Mg, and iodide. dKH was 6 or 7* where the tank normally runs around 7 to 8. Nothing looks unhappy at this point so I don't think it was the wrong decision. Thankfully I haven't had many "oh crap!" moments in the last year until this incident. I did have one loss, a small leather coral that was promptly removed to prevent potential toxin release. However, I don't believe it was related to the decrease in salinity, it entered what appeared to be a normal molt a week and a half to two(ish) weeks ago but just didn't open up again. I was being patient and not touching it and just letting it do it's thing. I suppose it could have been due to the high salinity though.