Keith A.
Aquarium Advice Activist
For the longest time, I have been using Instant Ocean for the salt in my 75 gallon reef tank. I do a 20% (15 gallons) water change every other week. I switched to Reef Chrystals about 5-6 months ago to help with the calcium levels in the water. When I was using IO, it would take me 2 1/2 metric cups (20 oz) of salt per 5 gallon bucket of water (three buckets, 7 1/2 metric cups, 60 oz total) in order to maintain the same salinity in the tank. Since I started using RC, it takes nearly 3 1/2 metric cups per 5 gallon bucket to maintain the same salinity. To my knowledge, both IO and RC are made by the same company. Is there a difference in the "potency" (if that's the right word I want to use) of the salt between IO and RC?
Keith
Keith