[Fox]

Originally Posted by Pan

Your salinity is low as is your ph...you also add to quickly. Don't listen to big als. Clean your fluval every week. Check your ammonia if it keeps rising the missing fish is probably decaying. You don't mention (or i Missed) a cleanup crew, this is an essential part of a tank as well.

Is t suggested that I tear the tank up in order to find and remove the goby??

I will start cleaning the fluval weekly with the water changes...I do have a CUC in there consisting over small burrowing snails, big (I think Turbo) snails and some little hermit crabs...they are all doing fine.

Originally Posted by Pan

Test your own water most lfs use the tests till they run out who knows if they have expired (this is not all LFS, but with big als...well).

I do test my own...lately I have been needing replacement fish and so I doubt my test results and want a second opinion...

Originally Posted by Pan

Remember most ammonia tests rely on a valid ph test as well...ph is a certain level then ammonia toxicity is higher or lower. Save your money, stabilize your tank then try again.

The point in adding fish slowly to a tank is to build up the bacteria you need...which needs ammonia to form..but a tank can only process so much at one time...the bacteria doesn't keep growing and growing...it grows as more ammonia is added...to much the system cannot cope....so you have to think of it like this...every time you add a fish you are essentially doing a little cycle.
also...since you are new...try testing your replacement water for everything you test your tank for...see how everything compares...

Thanks!