Thats about half of the good old idea .. for the last 40 yrs we have always used a piece of white plastic like a old bleach bottle or white sheet of paper and then we used a yellow crayon or marker to paint a yellow patch then if you look through the tank and can't see the yellow then you should have been running or change you carbon. Now tank length makes a difference. And if you run a refugium then you need carbon more as the water is more yellowish from the leeching chlorophylls _________ Some of the world's greatest feats were accomplished by people not smart enough to know they were impossible (Doug Larson) |