Lowering Alk

[MACH5]

Hello.
I would like to ask what would be the best way to lower my Alk on my newly mixed salt water. I just tested it and it's 12dkh. Need to bring it down to about 8 or so.

Thanks

[Percula9]

12dkh is still within normal range, it's the upper limit. Stop dosing buffer until alk goes down. Alk of 9-10 is a good range.

[bertoni]

What brand of salt is being used? How is SG being tested, and how was the device calibrated?

[MACH5]

Tropic Marin Pro. Refractometer calibrated with RO.

[bertoni]

I'd try calibrating with some of the PinPoint 53 mS solution. Calibration with RO/DI water can be very inaccurate:

http://reefkeeping.com/issues/2006-12/rhf/index.php

I think that result might be reasonable for that salt product, though. I'm not sure.

[MACH5]

Ok thanks bertoni... will do. I'm just trying to lower a bit my Alk. My tank runs about 8-9 dkh. My newly mixed water reads 12... so just want it to bring it closer.
I've read about using sparkling water to lower your Alk and so I tried it. But it seems that you need to dose quite a bit of it to bring it down. I put one liter into about 40 gal. of salt water and the Alk still about the same.

[bertoni]

Sparkling water won't lower the alkalinity. It just reduces pH temporarily. A mineral acid can lower the alkalinity, but they are a bit dangerous.

[MCsaxmaster]

Agreed, just stop dosing whatever you're dosing for alkalinity and wait a couple of days. It should drop on its own due to calcification.

[Billybeau1]

Many salt mixes like IO, RC and others make their salt mix that high on purpose.

Let's say your tank is at 9 dkh. You do a 25 % water change with a mix containing 12 dkh.

You will see very little difference in the rise in dkh in the main tank.

Conversely, if your tanks dkh is 9 and you keep doing water changes with water that is 9, you will continually have to add an alkalinity supplement to maintain your levels.

Instant Ocean @ 1.0264 runs about 12-13 dkh and no one seems to be having any problems with high alkalinity.

[MACH5]

Ok. Thank you all for your comments. Very helpful!

Billybeau1: It looks like I may be worrying too much. I agree, I guess a partial water change would not cause a significant rise in my Alk. At least not enough to stress the animals.

Thank you all

[Billybeau1]

:thumbsup: