Saltwater Fishtank.

Question
I had my 75 gallon saltwater fishtank for almost 2 weeks now. Tuesday the 3rd I'm aloud to get my first fish. However, it being such a wait to get any live creatures in my tank, I couldn't wait. So I bought two snails (which an employee said could be in the tank,) two regular shrimp and a fire shrimp. They were added into the tank after about a week. Everything was going fine. The snails were turning the live rocks green and moving around. The shrimp, however, seemed shy. They moved most with the tank-light off. One day, me and my roommates were scared to notice a dead shrimp, one of the regular of the two. We also noticed the Fire Shrimp had shed off it's skin. It was huge scare, since we thought it died, and that it being quite an expensive shrimp. In the midst of that scare we then noticed a clear-milky film on the surface of the tank. It looks as if it was sperm. I took a cleaner and dipped it in and the film floated around. It rests back on top of the tank. That's the problem at hand, what is this stuff. It's clear, sperm-like. Is it a disease in the water? I'm not sure how to handle this.

Answer
Hi Scott,

Well, first of all, you've made the usual mistakes a newbie to saltwater fish keeping does.  Putting fish in too early is a huge no no.  Not two weeks to cycle, either.  It's at least one month.  I don't know who's advising you, but putting fish of any type in now is a disaster waiting to happen.

Here's why:

Your tank is new.  It's not cycled.  That means bacteria hasn't grown which can fight the chemicals formed by poop and from the cycling process (aging of water, rock and sand).  Without having a super good skimmer on the tank, doing water changes every 3 days (you are doing this, right?), the tank is headed for a huge disaster very near in the future.  The white film is probably a bacteria formed by the water quality and you will lose your shimp, guaranteed, if not taken care of asap.

I would take out 25% of the water every weekend while it cycles for one month.  One month.  No less.

Changing water will help to combat any nitrates/nitrites or ammonia which form and believe me, it will form. :)

About six weeks down the road, you're going to get a gross, brown film on everything but don't panic.  That's normal.  That's the end of the cycle.  It will take about a month for that to go away, but during that month, you will need to change out 25% of the water every other weekend as well.

The shrimp dying is just the beginning.  The other will also, so you have to get that water quality fixed asap.

Drain at least 25% of the water today.  Skim the tank heavily...leave it on from now forward, not turning it off at all.  The skimmer is an essential, very important part of saltwater fish-keeping, as they require pristine conditions in order to thriving.

Also, seek better advice than that which you have been given. Any petstore who will sell you fish or inverts (besides snails which is what I recommend to begin the cycle), is not considering your finances.  They are WELL aware the shrimp will probably die.

That's not very honest of them, imo.

Encapsulating my advice:

1.  Water changes asap.  25% today, at least, and if you can change 35% more power to you.
2.  Water changes every single weekend of 25% while the tank is new and cycling.
3.  Water changes bi-weekly at the rate of 25% next month when you introduce the fish while the bacteria grows (beneficial bacteria) from their poo.
4.  Don't panic when you see a light brown film.  Just siphon it off.
5.  Today, clean the film from the top and heavily begin skimming the water to improve quality.  Do this right now.  Don't even wait to skim and do the water change.  The shrimp is one of the most sensitive animals.  If one died, then the other will follow if the water quality isn't taken care of.
6.  Tank cycles take a month or more.  Whoever advised 2 weeks was not considering the expense you will lose by rushing.  You will lose a lot of livestock for the first month/two months, etc., if you simply can't wait.

Happy fish-keeping.