what happened

So I set up cleaned and setup my hospital tank.Filled it with water from my LFS.Had it running for a couple days.Friday I added a wrasse to the tank and went on a weekend vacation.I get back Sunday evening and the tank looked white.At closer inspection and testing the water was clear and perams were fine but the glass and all surfaces of any plastic,heater,e.c.t. had a hard white film on it.I transferred the wrasse and emptied the tank.It took vinegar to get the film off of everything.
So what happened?

 

Was it topped off over the weekend? If it took vinegar to get off it sounds like a calcium carbonate precipitate.
What is the salinity?

 

I occasionally get a yellowish/white film on in my sump. I believe it's from calcium precipatation or alkalinity. However, I have never had it in my Dt.

 

It was not touched over the weekend and nothing was added.Everything was Good.Salinity was 1022, and the water was brand new, three days old.I did a calcium test and it was just over 500.Nitrites,Nitrates,ammonia was fine too.
From brand new super clean water to a heavy white film on everything even in the skimmer in 48 hours?

 

Only thing that comes to mind is that if it is an open top that something entered and contaminated the water. What is your Mag level?

 

The tank came with a stock hood so I dont think anything got in.I did re attach a piece in my skimmer with epoxy recently but i have done this before with with no negative effects.I also used a piece of a rubber glove to gasket the skimmer but again i have done this before with no negative effects.
Maybe the epoxy was not dry enough and bled???

 

You threw something out of balance and caused a cal precipitation. I'll bet your Mag is low. You said your Ca was at or over 500. If your Mg is low, your water will basically not be able to hold that much Ca, and puke it out. (Snow excess Ca). My Ca is at 500 also, but I use Oceanic salt which also has high Mg, so it balances out.

 

Ok so I have to admit that I am rather new to the hoppy and am still trying to learn.With that being said I do not currently test either my main tank or hospital tank for Mag levels.
Could you tell me how magnesium interacts with the tank and why i should be testing for it?So what could change mag levels so drastically in 48 hours?

 

I would personally say it is a cycle as it is new water from the lfs and not your tank with all the bacteria in it with the waste from the fish problaby started with High ammonia and went from there some fish are not capable of handling high swings and changes in Params.


and when you said cleaned up what did you clean it with? bleach and or something else?

 

Having a calcium of 500 with a salinity of 1.021 is tough to achieve. Usually a magnesium to calcium ratio is 3:1, meaning you would need a Magnesium of 1500 to essentially maintain a calcium of 500 without causing your alkalinity to sink and the pH to crash.
Even the most expensive salt brands will only give you a calcium of 480~ish at 1.025 salinity. (usually 420~ish at 1.021).

However, unless you added some type of alk or calcium supplement after adding this "new water", nothing should have precipitated as such. But since your saying its a crust that required vinegar to remove, it would appear as if it has. I have heard of strong electrical currents in water or objects causing rapid calcium deposits on them (They actually build artificial reefs in such a manner). So, you could possibly check for stray voltage, and see if there is a chance of that.

Id really like to know though, if the "film" was a calcerous crust, or just a thick film thats just hard to rub off?