Can you please review the following to ensure that I'm doing this right ?

If I have a medication (powder) that is 1 gram / 100gallons of water and I want to treat a 75gallon aquarium.

1 gram = 1mL

Let's say I take 1 gram and add it to a bottle of 40mL of water. Shake it up and then draw it up with a syringe that is in MLs.

Is this the correct dimensional analysis

30MLs x 1gram/100gallons x 75 gallons = 30 MLs

So then from the solution in the bottle I would draw up 30 mLs and add that to the fish tank?

Is this correct ?