Ammonia Spiking

Question
Hi Tyler,

I recently got a new tank for my saltwater fish for which I had had in an established tank. My new tank is a 45 litre tank. I also have a filter with it that hasn't been used in a while. My old tank is 20 litres...I put the water from my 20 litre established tank into my new tank and topped it up with fresh sea water. I also put my fish into the new tank. Will my water still go through ammonia spiking even with the already established tank's water in the new tank? Does my filter need to go through the cycle to be established. My fish are quite expensive so I don't want them to die.

Regards,
Liz

Answer
Hey Liz

Are you using any live rock? if you add rock to your new tank, and its cured, you wont have ammonia. If youre doing fish only, and rely on the filter, you still shouldnt have ammonia as long as the filter has been running.

The used water wont't do anything, in FOWLR or reefs, your LR is the best source of ammonia removal. In fish only, your filter is