How do I lower my alkalinity?

[ktrandc]

I'm still trying to figure out my ca reactor. Today I tested my water and my alk is at 18, my ca is 460, and my mag is 1550. How do I safely lower my alk to 9-10? I've already turned off the CO2 in my ca reactor. Should I do a large water change?

Also, I'm using lamotte's test kit for alk. Should I be multiplying the final titration (in ml) by .05 to get the reading? I think someone told me .05 or .056, but I forgot.

 

[Spssteven]

Water changes to get it down, seems to work the best. What's your ph? Also if you bring you mag up just a bit more your alk will also lower down a little too.

 

[Ian]

you take the # that's left in the syringe, say it's 145, and divide that by 17.86 which would give you a level of 8.11.

If your alk really is 18 you might want to do a series of smaller water changes to bring it down slowly. First verify it really is 18 though....

 

[ktrandc]

I took it to Age this afternoon, and had it tested. Then I went home and tested it myself. Both tests showed 18.

About 3 weeks ago I started dosing Kent Tech M to bring up my Mag to 1500 to get rid of some bryopsis. Could this have been the reason?

I'll start doing small water changes today to start bringing down the alk.

 

[lbaldrey]

Definitely water changes.

What made it go that high in the first place?

The link below has the manuals for the Alkalinity test using the three procedures at the bottom of the page...check which one is your method.
http://www.pollardwater.com/pages_product/LaMotteAlkalinitytks.asp#MANUALS_

 

[marfuerte]

+2 or was it 3 on the water changes. Google SaltyZoo--they have a conversion program--just plug in your reading and it will covert from ppm to dKh or meg/l.

I use LaMotte too and wrote down the conversions and keep it in the box.

 

[ktrandc]

I figured it out. It's either multiply by .056 or divide by 17.86.

I've done a 10 gallon water change. When should I do my next water change? Is tomorrow too soon?

 

[Kenfuzed]

Is your pH high as well? Elevated pH combined with high ALK will burn the tips of your coral. If your pH is very high (>8.7) then try adding seltzer water. A while back I accidentally overdosed the alk part of my 2-part. Using Sparklets sparkling water from the market I slowly brought down the pH to around 8.5 and dKH followed. The CO2 in sparkling or seltzer water will drive down pH and won't cause an algae bloom like adding vinegar. Regardless of method make changes slowly.

 

[ktrandc]

Thanks for the advice. I will measure my ph tomorrow.