How to lower DKH

the captive reef · Nov 2, 2010

Hey Guys,

I am having a problem with lowering my DKH, it is 11 and I want to lower it to 8. I am running Biopellets and with the ulns couple of the tips of my acros are burning. I am running a vertex calcium reactor and the PH for the effluent set by my controller is set at 7.1. My calcium is at 450 and my magnesium is at 1500. Phosphates are 0 and nitrates are at 0. Anyone know how I can bring it down?

thanks,

Mike

iani · Nov 2, 2010

Turn off your calcium reactor for a couple of days.

the captive reef · Nov 2, 2010

But when I turn it back on will it just go back to 11?

thanks,

Mike

sowellj · Nov 2, 2010

What brand salt are you using? If you are using something that has a high dKH to begin with, and your demand for carbonate is low, it may be tricky. If this is not the case, you will likely have to tweak the calcium reactor.

the captive reef · Nov 2, 2010

I use IO and the DKH is 8 (I tested it). When you say tweak it,should I raise the PH higher in the calcium reactor? Can I raise it to high and the media will not dissolve?
thanks for the help,

Mike

stunreefer · Nov 2, 2010

I've personally never seen IO test low in Alk. Generally right around 10 dKH and as high as 14 dKH IME.

the captive reef · Nov 2, 2010

I just tested it with an elos and sera test kit and they both read 8? I mix up 65 gallons at a time and have an auto water changer that does 3 gallons a day.

Mike

sowellj · Nov 3, 2010

the captive reef said:
I use IO and the DKH is 8 (I tested it). When you say tweak it,should I raise the PH higher in the calcium reactor? Can I raise it to high and the media will not dissolve?
thanks for the help,

Mike

You can raise the pH to a level where the media will not dissolve. Can you cut down on the effluent flow?

shapermike · Nov 3, 2010

Lower your return rate going back in to the tank from your reactor. but turning it off will let the system use up all the alk. it looks like you reactor is running away from you. it might not be set correctly. you prams dont look all that bad as long as they dont go up any higher

Reef lvr · Nov 3, 2010

I'm having same issue and i dont run a reactor. I am using IO also. I am confused!
Alk. 12.5
CAL.450
Mag 1480
PH. 8.1
SG 1.026

iani · Nov 3, 2010

If your alk is stable at 11 then no it will not go back up to 11. Your corals are pulling as much alk as the calcium reactor is adding. If you alk is slowly rising then yes it will move back up. If the latter is the case take the calcium reactor off line for 2-3 days and lower they effluent out of the calcium reactor. If the former is the case just taking the calcium reactor offline for a few days should solve the problem.

Murfman · Nov 3, 2010

the captive reef said:
Hey Guys,

I am having a problem with lowering my DKH, it is 11 and I want to lower it to 8. I am running Biopellets and with the ulns couple of the tips of my acros are burning. I am running a vertex calcium reactor and the PH for the effluent set by my controller is set at 7.1. My calcium is at 450 and my magnesium is at 1500. Phosphates are 0 and nitrates are at 0. Anyone know how I can bring it down?

thanks,

Mike

Calcareous material starts to dissolve around a pH of 7.0 and lower. Too low and you create a slurry of dissolved calcium. Too high and you don't break it down. I Don't think you are getting a lot of Ca with your reactor set for 7.1. I have mine set to come on at less than 6.6 and off at more than 6.7. As for your alk being 11, that is not too high 7-11 is considered acceptable. 7.0 is what natural sea water is at.

Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com

Ricordea · Nov 3, 2010

know what you mean when using IO salt or Reefcrystals,known for high DKH.Yes turning down or shut off reactor will help.I got this info on another board.But here ya go.I down size my system,where a reactor wasn't need.And recently went to the Bio pellets,but wasn't happy with the always high DKH values from these 2 salts either.Yes could have went to Brightwell salts,but the cost of that turned me off.I wanted another method.So here ya go.Muriatic acid (pool).you will need to use0.123miof acid to reduce1 gallon of salt mix 1DKH.Use half that amount stir your salt mix thouroughly to allow CO2 to dissipate and test your results.
Example,
If you want to reduce 20 gallons of salt mix say 5 DKH,than you would want to use:
20 x 5x 0.123 =12.3 mi acid to reduce 20 gal. 5 DKH (USE 1/2 of this amount to start with).
You need to mix salt really good to remove any CO2 from the reaction before you test for Alk and add it to your tank.Then if needed you can add more,for desire levels.
DO NOT REDUCE ALK METHOD IN YOUR TANK !Because fish/corals ect......

dakotasreef · Nov 3, 2010

I think something needs to be adjusted. It should just maintain your cal/alk not raise it.

the captive reef · Nov 3, 2010

thanks everyone, I have slowed down the water coming out of the reactor and will see what happens.

Mike

mrwizard421 · Dec 29, 2015

Hi i know this is a old thread but I'm having this problem.. I not dosing in any way.. But have tap water.. Rodi hopefully coming in today . but can i lower the calcium and kh in a treatment or just continue water changes until lower level is reached..?
Dkh. 19
Cal. 560
No mg test
Po4. Less than. .25
Sal. 34
Temp. 78.5

Singlefin · Dec 29, 2015

How did it get so high? I would say bad test kit or method. Water changes would bring it down safely. What salt are you using?

mrwizard421 · Dec 29, 2015

Lol Im not sure... But my GH of my tap Water is 15dkh. So I'm thinking That's what is helping the high level. I don't dose and I'm using instant ocean reef crystal i know its a higher alk. salt, but this level is crazy.
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