unit burning out quick is something that can he can not make a general statement about.
It all depends on your water... I burn through DI
quicker then some other guys i know in my reef club, others go through more then me..
My friend has used the samd DI
for over a year now with 0-1 TDS
. When using 1 Di
I was going through about 1 cartridge every 200 gallons of water made. I run dual Di
now and they last a lot longer...
Bottom line is, is your water quality good in the tank? Low nitrate, No phosphates and no nusinance algaes... If these are all good then using a DI
may not be needed for you.