Raising salinity

[bodicea]

I am slowly raising the salinity of the tank that holds my F8's. The tank was completely cycled at zero Amonia, zero Nitrite, and about 10 ppm nitrate. I added about three tablespoons of marine salt. I mixed it with treated, aged tap water, left overnight with an airstone running in it. 24 hours after adding it I retested the water and the ammonia is up to 0.35 parts per million, zero nitrites and less that 10 ppm nitrate. So did I add too much salt at once or is it normal for the bio filter to be affected by the salt. What is the best way to deal with the fluctuations?

Thanks
Jan

[chubber]

Alright Jan,

It depends on the jump in salinity, but an increase in ammonia is not a good thing and should not be happening. The bacteria in a cycled tank my be killed off if the salinity changes too fast, causing increases in ammonia and nitrite. The key is to change things slowly so that the bio filter is not "upset". Do you know what the salinity was before and after you added the salt? Without knowing the volume of water in your tank its a bit tricky to say whether 3 table spoons would have caused a problem, but unless it is quite a small tank i wouldn't have thought so.

I think the best way to get around the ammonia issue is to carry out regular large water changes until your system stabalises again. Match the salinity of the water changes with the current salinity in the tank.

Could you please post your tank size and salinity?

How are the F8s?

Cheers

[Dadof4]

The most you can bring you SG up or down in one week is .002 without killing your bacterial filter. When I raise the salinity of my tanks I do it by doing 50% water changes. If the tank started at 1.000 (fresh water) and you want to bring it up to 1.002 SG, you want to do a 50% water change with the premixed water being 1.004. Averages out to 1.002 when mixed. You do need to use a hydrometer or refactometer when you are changing your SG to make sure that you haven't went over the desired amount.