how much salt

[loveforfish]

i want to change my freshwater 55 gallon to strong brackish. how much salt do i add a day to aclimate it properly.. i dont want to drain it or kill the cycle?

[leebca]

It is uncertain that you can 'save the cycle.' The bacteria working in freshwater may not convert. However, in a few weeks new bacteria will settle in to run the cycle.

The bacteria may make an adjustment with small additions of salt. I would recommend to take the total amount of salt you will need to add and put in 10% of that every 2 days. Some water should be removed, the salt added and mix in properly, then that water added back to the system.

You can see this will take about 20 days (3 weeks) which is about 3 weeks faster than just making the change and waiting for the bacteria to start up. Yet this process won't guarantee the bacteria will still function. They can and do sometimes go into a metabolic 'hold pattern' while they adjust, which means they won't either function or not function up to their ability during the transition period.

You need to feed the bacteria during the process (i.e., provide a source of ammonia nitrogen waste products).

Let us know how it turns out.