Blue-green in uplift

I have a 15g, fairly densely planted tank, ugf, CO2 (I know, I
know....), medium/heavy fish load. All is well except I have HORRIBLE
algea in the uplift tubes, mainly blue-green, but generally just
mucky. What to do? I have thought of leaving the filter off for a
while to see if any of my algae eating types fancy a visit to algae
heaven (or hell) Or maybe dropping a couple of snails in?!
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