High PH low alk what gives?

[polyppetey]

did my weekly tests today and found I have a

8.8 PH

7 DKH alk.

Calcium is at 420.

Salinity 1.026.

Mag 1300

Nitrate0

nitrites 0

phosphates 0

Ammonia- the test it hard to rread but looks to be at 0 or close to it.

temp 80F

 

I do not dose much, I have been gradually adding mag over the last 3 weeks to get it to 1350.

Alkalinity has been a problem for me, I can get it to 9-10 DKH but in 2-3 days it goes right back to 7-7.5 DKH.

 

My critters are looking good with the exception of my snails who are acting weird, not moving much. This has neen going on as I got the mag over the 1100 mark.

 

Usually the PH is 8.2 8.4 range. I tested it right before the lights went off and will post another test tomorrow AM. and do a 10%WC.

 

Thanks.

[lakshwadeep]

Did you retest the pH?

 

Try using these articles (to convert dKH to meq/L, divide by 2.8)

High pH

http://reefkeeping.com/issues/2005-03/rhf/index.php

Solving calcium/alkalinity problems

http://www.advancedaquarist.com/issues/nov2002/chem.htm

[polyppetey]

I did a 20% wc and it dropped to 8.4.then back to 8.8 at the end of the day, i retested twice though the alk is now 10 dkh after the wc.

 

Thank you for the help lakshwadeep you always post where others fear to tread.

[lakshwadeep]

You might want to test with a separate kit. Also, search for whether the magnesium supplement causes pH issues; perhaps there is something that doesn't affect alkalinity but causes high pH.

[polyppetey]

I use the kent marine magnesium, one thing though is that now thst it is nice`we leave the windows open all day, less co2 in the house??

My skimmer broke too that may have something to with it??

[mxpro32]

The skimmer breaking should lower your ph.

[jgrivna]

about 67% of carbonate ions in seawater exist as ionic pairs with magnesium. Im guessing that as you add your magnesium its essentially sucking up your alkalinity and causing the inconsistency in the pH that you've been seeing.

[lakshwadeep]

jgrivna: ion pairing may occur, but I don't think that should stop an alkalinity test from measuring the carbonate/bicarbonate ions.

 

An article on the connections between calcium, alkalinity, magnesium, and pH:

http://reefkeeping.com/issues/2006-06/rhf/index.php

[Amphiprion1]

It is true that there is substantial ion pairing involved between CO3-- and Mg++, but it does not really affect test results.

[dweebikus]

I was just looking for info because I'm seeing something similar. My dKH is in the 7 range. But my calcium is around 400, my mag is a little above 1200 and my ph is above 8 (I think around 8.4 or so). Is 7 actually a "bad" reading for dKH? Should I really we worried about raising it?