rmosqued, I hate to do this to you but you need to seriously consider your regulator. Milwaukee regulators are notoriously bad when it comes to metering low flow. To me, that is one of the wekest links in your system. It wouldn't matter what kind of Ca reactor you had, the regulator is going to cause stability problems. By all means do the 1502 mod, it will make a HUGE difference. But you need to ditch that regulator. I know they're pricey but the aquariumplants.com electronic ones are THE BOMB in my opinion. $189.99 for the electronic regulator or $289.99 if you need to have an LCD read-out (for whatever reason).