Here is a idea from a HUGE thread over at RC debating the pros and cons of a DSB ... the general consensus at this late stage of the thread ( 45 pages long !

) is that a DSB will work OK for a few years but is destined to leech phosphates after about the 4 yr mark and thus cause algae blooms ... so the pendulum has swung in the other direction at least from the most vocal in this particular group ... this poster came into the thread late but with a interesting suggestion ... it might be the most logical thing to come out of that thread so far

... take a look and lets get some comments on it ...