View Full Version : Help with Alk and Kent Marine Superbuffer

03/23/2012, 10:38 PM
I have had a 40B running for about 3.5 years with almost zero supplementation. Weekly water changes have kept up very well and still are to a degree. My LPS, montis and millis have good growth, color and decent PE but I think they can look better. My current tests are..

Mg 1420
Ca 440
Alk 6 to 6.2 dKh

I was advised by my LFS to raise alkalinity (which will drive some Mg out of solution) and my Ca and Alk will level off. They advised adding a 1/8 to 1/4 tsp of Kent Superbuffer to my water change water to boost alk and test at 2 and 6 days to watch the drop (if any). I don't have an auto top off or other way to drip kalkwasser. It was also suggested to mix my WC water to ~15dKH in hopes of bringing the alk to around 8 to 9. That seems like a big jump in one water change?

I do an 8 gallon water change on a 50ish volume (including the sump and subtracting out rock displacement) every week using Brightwells Neomarine salt. Again, my tank is not struggling so I don't want to add anything if I don't have to. I would prefer to keep things as simple as I can for as long as I can. Appreciate any suggestions!

My SG was 1.026 at the time those results were taken using a trusted hydrometer and 2 calibrated refractometers.

03/23/2012, 11:51 PM
Raising the alkalinity won't affect magnesium, nor will it change calcium in any meaningful way. I would use some baking soda to raise the dKH to at least 7-8, and do some daily measurements to see how much the tank needs on a daily basis. If you start adding a significant amount of alkalinity, which is fairly likely, you'll need to supplement calcium, too. A 2-part, either commercial or DIY, is an easy way to get started.

Water changes seldom can keep up with the alkalinity consumption of a tank. The SuperBuffer is an okay product, but it's mostly baking soda with some sodium carbonate. Off-the-shelf is cheaper. :)

This calculator will help with a dose:


This article covers dosing in more detail:


03/24/2012, 08:42 PM
Thank you! I'm both embarrassed and happy to confess this but I did my water change today and thought I'd better test one more time before I start with the baking soda. So glad I did! My alk is actually right at 10 (not 6). I have a Salifert kit for alk but everything else is a Red Sea kit. The RS kits you subtract your remaining agent from 100 to get your result but the Salifert you just read the scale and that number is your result. Almost dosed for no reason.

I have tested everything twice now and Mg is 1420-1440, Alk is 10 dKH and Ca is 440-460. Have to say I am pretty pleased that my salt mix is keeping me in check.

03/26/2012, 12:03 AM
Okay, those number are fine!