IU's
from Dodolah
doesnt answer question but explains the issues with iu. a liquid vitamin would likely have the IU per ml listed
for example childrens polyvisol has 1500 IU of Vitamin A per 1ml (lots more stuff in there also)
maybe we could use it without the iron. i do not have...
you can get a reptile water conditioner or if the chlorine is actually chlorine (not some super powered chlorination, iforgot the actual chemical) allow a bucket to sit overnight and it will evaporate out then put it in your reservoir
good luck
Sean