I decided to throw my two cents in here on two-part. I've had SPS corals for years and have been reefing since 1990 but have never gotten into a full-blown dosing method until I set up my rimless system with intentions to do an SPS dominant mixed reef. I researched salt mixes looking for a mix that has higher numbers of Alk, Calc, and Mag and was reasonably priced. I had been using Aquaforest for a time but the numbers on new mix were lower than what I was looking for, and I got to thinking about the fact that over the course of more than 25 years of keeping reef systems I used Kent Superbuffer dKH all the time on mixed reefs for pH and Alk and always had good success in maintaining numbers (along with weekly water changes of course). Based on the high quality of that product I decided to have a look at Kent Reef Salt. The numbers at mix are higher than most, which is what I was looking for so I ordered a bucket.
In the meantime, I was looking at info from other reefers regarding two-part and came across a link to a blog by Joe Jaworski and read his take on two-part, wherein he writes about how critical it is to use two-part where both parts are from the same manufacturer because they're geared to work together and how many folks aren't successful with dosing because they use product from different manufacturers that are not designed for each other. That made sense to me and I decided to take it one step further and go with Kent's Two-Part Tech CB because I had already decided to use Kent Reef Salt due to the higher numbers at mix.
I should add that between the time I started using the Kent Reef Salt and Kent Two-Part Tech CB, my numbers were fluctuating regularly and before adding higher end SPS I wanted to get my numbers spot on and consistent. For anyone who might be interested, here's the link to Joe's blog where you can read his full article:
https://joejaworski.wordpress.com.
In his article, Joe also suggests testing Alk, Calc, and Mag on a new batch of your mix so you know what you have while attempting to get your numbers in line. I mixed a batch of Kent Reef Salt and as stated on the label, my Calc at mix to 1.026 was 440, ph was 8.3, and Mag was 1450. I also tested Alk, and it was at 10.3 at mix. I then did a 20G water change (100G total tank volume) with the mix. I waited a day to recheck my numbers, and low and behold my pH was at 8.3, Alk was 10, Calc was 420, and Mag was 1350. These were the best numbers I'd had in some time. I tested the numbers for a couple days thereafter and they dropped off a bit so I started dosing the Kent Tech CB two-part using the methods Joe describes in his article. One of the main things he emphasizes is after you do your first two-part dose, wait a full week before you test your numbers because it takes some time for them to balance out. As he suggested, I waited a week and tested all numbers and they were spot on! Alk was 10, Calc 420, Mag 1400, pH 8.3! These are the numbers I'm seeing regularly now using the Kent Reef Salt and Kent Two-Part Tech CB. I used the dosage recommended by Kent on their containers, but Joe does offer dosing numbers, too. If you're having issues with getting your numbers where they need to be, have a look at Joe Jaworski's two-part article. He also does his best to answer any questions you might have about dosing. You may also want to have a look at Kent Reef Salt and their two-part Tech CB, too.
The other great thing Joe suggests if you don't already have a dosing system and will be doing it manually, pick up Bettix bottles for dosing. They're simple to use (one for each part of your two-part) and accurate in doses. I ordered mine from Bulk Reef and they work great! I hope this information is helpful to those who have struggled with dosing over time. Happy reefing!
