Normal JDs are very comfortable in brackish situations, so you can easily bring the salinity above 3 ppt (parts per thousand) which kills emerging ick tomites. I throw rock salt in over 24 hours by the handful, until my condutivity/salinity meter reads just above 3ppt. (some ick wil survive if under 3ppt)
I have snorkeled with the normal type in brackish cenotes in Mexico, but I cannot speak to the EBs.
If the salt treatment doesn't work, any over the counter malachite medication dosed according to manufacture directions should work.