Wade Posted April 15, 2014 Share Posted April 15, 2014 Apparently you can find the answer to any question on the internet except this simple one. How do I lower the alkalinity in my fresh saltwater batch? I used the BRS calculator to raise it, but it raised it too much (makes me now question my alkalinity mix). I would now like to lower it so it closer to what's in my DT. How do I do that? Quote Link to comment Share on other sites More sharing options...
Dean Posted April 15, 2014 Share Posted April 15, 2014 I know that start smart bacteria will lower alkalinity if that helps.... - Dean Quote Link to comment Share on other sites More sharing options...
jestep Posted April 15, 2014 Share Posted April 15, 2014 What did you raise it with? Quote Link to comment Share on other sites More sharing options...
Wade Posted April 15, 2014 Author Share Posted April 15, 2014 BRS 2-part soda ash according to the BRS calculator. I've got 35 gallons of fresh sw mixed up. Quote Link to comment Share on other sites More sharing options...
jestep Posted April 15, 2014 Share Posted April 15, 2014 Mixing a larger batch of salt water to dilute it would be the easiest. Only way to actually remove it would be it being used up or precipitated out, neither of which are likely while it's sitting statically in a container. Does it need to come down a lot? Quote Link to comment Share on other sites More sharing options...
Wade Posted April 15, 2014 Author Share Posted April 15, 2014 it's at 11.7 and the tank water is at 9. I wanted to lower the tank water down to 8 so I guess I screwed that up. OK. I'll add another 15 gallons which should dilute it by 1/3 of the way bewteen 7.2 and 11.7. That should bring it down by 1.5 which is still only 10.2. I may just dump the whole **** batch ans start over. Aggravating as hell. That'll teach me to just add a little and test, add a little and test. Quote Link to comment Share on other sites More sharing options...
Bpb Posted April 15, 2014 Share Posted April 15, 2014 (edited) Dose calcium and that should lower it. Couldn't tell you how much just know they when an inverse reaction to each other. Either way DONT dump it. Horrible waste. I do 10% wc all the time with 12 dkh alk on my 8.5 dkh sps tank with zero issue. Stuff actually looks instantly better for a while but I think that's more likely due to the influx of fresh water and trace elements. Have tested before and after a water change and not noticed any significant difference in measured alk. Edited April 15, 2014 by Bpb 1 Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted April 15, 2014 Share Posted April 15, 2014 I would stick with Jestep's advice and just mix some more saltwater to dilute it. Adding Ca will only lower the concentration of alk if it is a high enough concentration to cause abiotic precipitation. You will basically bind your Ca and Alk and create a snowstorm of calcium carbonate. That'll basically convert usable Ca and usable Alk into a solid form that is not useful to our corals in its current form. Bpb brings up a good point... we must keep in mind the volume of the newly mixed saltwater and the tank volume. If you are just doing a 10%-20% water change with a higher dKh value with the newly mixed water, then its overall effect on the total system dKh may be minimal, depending on the concentration of Alk per volume of saltwater. I could probably mix up 5 gallons of newly mixed saltwater with a dKh value of 11 and add it to my total system volume of 250 gallons at a dKh value of 8 and see very minimal effects. Quote Link to comment Share on other sites More sharing options...
Wade Posted April 15, 2014 Author Share Posted April 15, 2014 yeah I probably would have been fine going with the 7.2 on a system that's at 9, but no good dead goes unpunished. I probably go overboard trying to make sure I don't make any mistakes. My new SPS is looking so good that I want to make sure I don't do anything that might have a negative impact. Quote Link to comment Share on other sites More sharing options...
Wade Posted April 15, 2014 Author Share Posted April 15, 2014 OK I added another 15 gallons to the drum with the salt mix. The alkalinity is now 8.2 so I'm in good shape. Much ado about nothing it seems. At least I learned a little aquarium chemistry:) Quote Link to comment Share on other sites More sharing options...
Wade Posted April 16, 2014 Author Share Posted April 16, 2014 Did a 15g wc (roughly 20%) last night. My pH is still running higher than I'd like. It's 8.52 right now. I did vacuum a section of the tank to remove detritus. I'll test the alkalinity when I get home to see where it's at. I don't expect that it's changed any. My carbon was almost completed blocked. It's been two weeks since I changed it and it showed. I'll be watching that closer and make sure it's done weekly even if I don't do a water change weekly. I would have thought some fresh carbon would have brought the pH down a bit, but apparently not. I'll have to get back to doing 5 - 10% water changes every 7 - 10 days. Things were more stable then. Vacuuming takes more time which results in a larger than desired wc. I guess more frequent wc's where I vacuum a smaller section will do the trick. Will kalk dosing cause the pH to rise? Quote Link to comment Share on other sites More sharing options...
Wade Posted April 17, 2014 Author Share Posted April 17, 2014 I slowly added 25ml of vinegar to the sump last night and it brought the pH down from 8.53 to 8.46. Today the highest it's reached is 8.41 so it looks like all is well again. Thanks all. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.