is this
http://www.purelyh2o.com/cart.php?ta...category_id=24

and this
http://www.purelyh2o.com/cart.php?ta...category_id=25

an alternative for this

http://www.purelyh2o.com/cart.php?ta...category_id=14

also I am using a Coralife version of this
http://www.purelyh2o.com/cart.php?ta...category_id=13

and am unsure which of these things is bad. My TDS is about 25 and I am thinking it is the little blue cylinder thing, but am wondering if that blue thing is dead if my mixed bed thing is also dead. I hhave only put about 100 gallons through this thing since it was new, but I didnt do any flushing and am wondering if that is why my TDS sucks. let me know folks....

Randy