Killing Things

Hanna phosphate photometers are good too. A little more expensive than the other test kit, but I love mine. I have the alk photometer too and they are both great. I use Salifert for my other test kits, but I've heard great things about Lamotte test kits too. Lamotte test kits use refillable reagents vs. buying a whole new kit each time so while the up front cost is more, by the time you've gone through two kits, your costs are equal, then you start saving money by using the Lamotte kits.
And as for your alk, that's a tough one.  I usually just wait for mine to go down, but without things to use up the carbonate in the water, it's going to stay high...especially since your water changes are adding fresh, high alk water to the tank every week.   I've heard of using vinegar to bring alk down, but I would stay away from that for the time being.
As some of the others mentioned, maybe the biopellet reactor is at the center of your issues.  Maybe you don't have enough of a nitrate issue to worry about having it online.  As it was suggested, reduce the flow to nothing over the course of a few weeks.  Let the bacteria colonies build up on your rock and sand and let that take care of your nitrates for now.  You may also want to look into getting a GFO reactor because taking the biopellets offline will probably also increase your PO4 present.  GFO can take care of that.  I hope this helps...
--AJ

 

I dragged bill over to my place to see what was up with my SPS color. Add More FISH...Added more fish....2 weeks later color was much better. I would do like Bill suggests. Just do it in moderation leave the BP alone I don't know your system but most your bacteria is probably in there. You take it off line, add more fish and feed the **** out your tank...well you get the idea. I would get the test kits and make sure every things ok there. I dont know how you fell about tangs but all mine did was eat and poop alot.   

 

Here are the ones I had.
http://www.liveaquaria.com/product/prod_display.cfm?c=15+20+1512&pcatid=1512