Cannot say enough good things about this scrubber. It is just what my tank needed. My ph is rock solid now, high 8.35, low 8.15 continuously, every day. A little over 3 weeks in & I have used up 1/2 of the first stage. Not sure how others are having trouble seeing the color change. It is extremely stark & very easy to see here. I have a picture but seems they don't let you post pics here. But it is a very noticeable purple color. At this rate I should get around 12-13 weeks before both are exhausted. Again, recirculating this through the skimmer lid with zero ambient air added. I do have a tee with a ball valve in the line but haven't had to open it. Hasn't seemed to effect the skimmer in any adverse way. The chambers are kept moist by the moist air coming from the skimmer. I do have another tee/ball valve cut into the intake line and I do have to open it once/day to drain the water from the line, so there is that. But benefits are far outweighing that minor drawback.

Day 1 I put this online around 7pm, lights had just started sunsetting & PH was at 8.0 (peak PH for my tank, low was always around 7.8). I checked 3 hrs later, lights completely out & PH had risen to 8.04. I was shocked! It actually rose further to 8.06 a couple hours later & never dropped below that the entire night! The next day lights came on & PH steadily rose throughout the day & peaked at 8.33! Excellent results IMO! I have an Octo skimmer & I bought the Co2 lid so it's constantly recirculating the moist air coming out of the skimmer. Four days now & PH has not dropped below 8.05 & always peaks around 8.33. Much, much better results than I had hoped for. I have seen no change in the color of the media yet. If the media lasts 4 weeks or more, I consider this money well spent. The thing is enormous (and heavy!), as others have mentioned. But I have plenty of room as my sump is behind the wall in an unfinished area of my basement. I hung it on the wall just above my sump with three 120lb toggle bolts. I could see how this thing would be extremely difficult to hide & service inside a stand with a sump.

So this is a follow up from my first review. I have this thing running a few days now and I'm pretty much getting the same results just like my smaller and less hassle co2 scrubber. Kinda disappointed because I was expecting a fairly decent jump in my ph. At night my ph is 7.9 and when the lights are on its around 8.07...pretty much the same like before. I haven't tried the recirculating method as yet because I need to get the correct fittings for the other side of the scrubber...I was hoping at least BRS sold those but nope.

Ok, some people said that this thing is big...yeah..that's an understatement...this thing is beyond big. I thought the space I had to put it would be big enough...nope, I was wrong by a long shot. Some how I was able to fit this monster under my tank. But so far my Ph has been rising steadily. So I would say that it works...just really really plan for the size.

Got this in mid July, still haven't had to change media. My ph didn't sky rocket, but has started to be more stable. Before adding this my highest ph was 77.5 now it's about 8.16, I do run this the recirculation way, that's why I haven't gone through the media.

Plan plenty of room! I mean plenty. I don't know where or how I'll mount this thing but amazing quality and connections. Definitely worth the buy. Seriously, the construction and engineering is second to none.