Freshly Mixed Saltwater has a Fishy Odour?

I just mixed up some new saltwater in a 20 gallon Brute container using Red Sea Pro salt. I noticed a couple odd things about it though, for one the pump developed a tough white film on the side facing towards the water surface, secondly it has some greyish/brownish debris floating around in the water and on the sruface. Finally, it has a slight fish odour to it. The water has only been mixing for about 3 or 4 hours. used to get a little bit of debris in the water before, but not this much. Is this something to be concerned about?

 

The brown stuff is likely clay. Since it's inert, it's not a problem.

I don't ever remember a fish smell so I can't help you there. How are you mixing it? Are you adding the salt to the water to mix it or are you adding water to the salt? If you add the water to the salt, you can sometimes get a precipitation event (which would explain the Calcium Carbonate deposit on the pump).

After you finish mixing this batch, soak the pump in a Vinegar/water solution to dissolve the Calcium Carbonate.

 

Do you make your own RO/DI water? DI will have a funky smell when the resin is about exhausted.

 

I do use my make my own RO/DI, TDS measured it at 004, I've heard that while while 000 TDS is optimal that under 005 is okay. I added the salt to the water, so I'm not sure if the issue is precipitation. I should also add that I lent this pump to a friend for him to make some saltwater and it may have been sitting in the water for a week or so, I don't think it would cause a problem, so I haven't mentioned it until now.