Help me with my fish room

So im gonna start my fish room soon and have a question, my utility sink is too short to utilize my washer drain so, can saltwater i dump down the drain be ok if theres a hose goin from my sink to the floor drain? The drain handles rain water (leaky wall) and 2 gallons from my dehumidifier but its a dirt bottom with a hole goin into the main sewer drain. Its an older home 1926 but no orangeburg.

 

The house was built in 1926. All the plumbing is new but where it hits the floor it changes to cast about a foot from the floor. Im not sure what the floor drain is under the cement