So I am ready to begin the battle against dinoflagellates in my 90g reef tank. I have confirmed that what I am seeing in my tank is dinoflagellates and not cyanobacteria by taking a sample into the lab and taking a look under the microscope. Easy ID. As expected, it is dinoflagellates. It was hard to take a good picture through the microscope with my iPhone.. Additionally, I am familiar with what cyanobacteria and diatoms look like (both in the aquarium and under the microscope) and this is clearly not either of them. Previously I was under the assumption that dinoflagellates were something that comes into the aquarium on frags, LR, etc. However, in the past 6 months, I have only bought one frag (and no live rock at all), which I bought around 3 months ago... This made me wonder how I actually got dinoflagellates. Is it something that always exists in the aquarium, but is only able to take over under certain conditions? I take care of my tank well (25% weekly WC's, change GFO regularly, use RO/DI, limit feeding, don't add supplements of unknown composition, etc). One problem that I have had recently is my pH was very low. However, I have realized that my pH probe is not functioning properly. It seems to be reading 0.15 less than it should. I calibrated it about 3 weeks ago. Taking this into consideration, I believe my pH is approximately 7.8. It seems as though pH influences the growth of dinoflagellates, and from this information I am assuming that this dino outbreak is a result of my pH being low. So here is the plan. I am going to go with corallines advice in the following thread that helped the OP to beat dinoflagellates: http://www.3reef.com/forums/algae/dinoflagellates-139342.html One problem regarding my water chemistry. I plan on increasing my pH to 8.3. However, I just tested my alk, and it is 10.2 dKh. I added enough sodium carbonate solution (BRS recipe) to raise the alk to 11.2 dKH, in hopes of increasing my pH. However, my pH only increased to 7.96. I don't want to add any more of this solution because my alk is already very high.. My calcium is around 450 and mag is around 1350. Hmm. What is the highest I can increase my alk to? I understand that it is not optimal for the SPS and other inhabitants to exceed 11 or 12 dKH. But I am wondering how much higher I can go without KILLING the inhabitants... Any ideas.. I see one more potential option to increase the pH. That is, to increase the pH without increasing the alk (i.e. using a different supplement that does not contain carbonate). My first though was to add some other base like sodium hydroxide. After a little research, I noticed that the product "API pH up" contains sodium hydroxide rather than sodium carbonate. I don't usually like to buy supplements like that.. But this seems like the best way to increase my pH without increasing alkalinity. Any advice here?