Done both and prefer a CA reactor. A bit of a hassle to dial in, but the coral growth has been better.

Almost certain that I will be getting Ca reactor now. Seems like I get more postive feedback on the reactor in sps tank.

I guess I will be looking for. Co2 tank, regulator with solenoid, reactor, and a ph probe add-on to my rkl. And I missing anything else??

Hmmmm.... Sounds like an expensive and busy holiday season for me

+1 on the reactor, like many have said, big initial cost, after that it's pretty pain free. I picked up mine used, great deal. The only issue's i've had with mine have been air lock in the lines, but i think i've fixed that with shorter lines now and everythings been going great. Reading about it online everyone was saying how difficult it was to dial in, I've found it very simple. I set it to the avg stocked tank recomendation, then tinkered for a couple days, and my PH/ALK have been perfect since.

The PH probe can make it easier to set up, i don't use a PH auto shut off, never had any problems. The only thing that could go REALLY wrong would be extra CO2, and i have no idea how that could happen. (Insert crash stories here?). Temporary extra flow will raise the PH in your reactor making it less efficient, but won't nuke your tank unless your reactors very big. And yes, moving hoses around and stuff one day you will bump the adjustment and realize your 1 drop a second has become 5 :S

My recomendation to make it even easier would be a good needle valve for CO2 flow. And pick up a bottle of 2 part for while you set up, Reactors are made to hold your levels not build them, you'll be constantly fighting it if you try to pick up your ca/alk with a reactor.

If you have it hooked to a controller it makes it even easier (a ca reactor) to dial in. I just set it so that if ph in the reactor is greater than 6.8, then turn co2 on, and if it's less then 6.7 turn it off. Then I really don't care as to what the bubble count of my CO2 is at. Hope this helps. I found it easiest also to T off my return pump a 1/4" flexible hose to feed the reactor. I used to gravity feed but I found that after a few months it would get clogged. Hope this helps.

now that sounds really easy to setup after spending $$$.

anyone tried or heard anything about Vertex reactor? Looks fancy from the picture.

Not sure about there ca reactor, but the Zeo reactor and media reactors are really well built.