Sediment filter and GAC filter for reef saltwater?

[mushy coral]

Ive never test the tds of my water before. Im using a 4 stages filter with a sediment, gac, RO and i dont know the last one. Yesterday when im taking some water from the filter to put in my new tank to cycle, i notice the sediment and gac need to be change. I want to ask if the water is still usable or not cause i mix it all with salt and i dont really want to throw it away.

 

[lapin]

It’s fine.
Change the filters

 

[mushy coral]

It’s fine.
Change the filters

Means that i can still use the watermix that i took from the failed core filter, great. Will it have any effect in the longrun? This tank Im plan to put in sps lps soft and anemone