High dKH

jacklax

Member
Will raising my calcium levels help to lower my dKH if I have a low calcium reading (FOWLR) and a high dKH? ph is consistantly 8.2.
 

jacklax

Member
Thanks. I consistantly do a 10 gal change (75 gal tank) each week. dKH was a 16 last time I checked. In the middle of hypo right now...is the ph buffer responsible for the high dKH?
 

mrdc

Active Member
A buffer like kent supperbuffer can raise it high if you continue to use it when it's not needed. It happens to a lot of people who try to raise their PH level with a buffer product. What is your calcium level?
 

jacklax

Member
While in the process of lowering the salinity I added ph buffer to the fresh water...it's my understanding that it has a much lower ph than salt water. I use Oceanic salt...but the amount is very low right now. My Cal readings are in the low 300's...320 range.
 

reefnut

Active Member
Your dkh is high due to the buffer and your calcium is low due to the high dkh and low salinity. I'm not much up on the hypo procedures but I wouldn't do much until you come out of hypo. Stick with the water changes and the dkh will fall on its own.
 

jacklax

Member
Gotcha...that's what I figured...just wanted to make sure I was on the right track. 3 weeks down with 3 to go in hypo...then it's the gradual climb back up.
 

mrdc

Active Member
I'm probably not the right guy to be helping since I am having calcium issues myself. Do you test the alklinity and ph on the freshwater after adding the buffer. How often are you adding the buffer? Each time you add it, it's building up more and more in your tank. The high dkH is lowering your calcium. I think the correct alkalinty and calcium level will produce the right PH. Not real sure. Reefnut needs to chime back in.
 

jacklax

Member
Good point...I have not tested the fresh water after buffering. That's a great idea! I had buffered all of the freashwater (per the directions) as I was decending into hypo...and buffer my top off as well. Beth had recommended watching the ph like crazy when going into hypo.
Everything I have read states that mixed saltwater has adequate ph, cal, and dHk...hence the importance of water changes. I'm just not able to mix full power saltwater at this time.
 

kimgpk

Member
I am having the same problem and i have not used a buffering agent. Although I do not have a cal test kit (should I have one ) and I am not sure what dHk is could some one help me out.
 

mrdc

Active Member
Yes you should have a calcium test especially if you house stony corals. Dkh is an alkalinity measurement. You test may read in meg/L and the conversion rate to dkh is 2.8 (that's what I have been using..found it on the internet).
 

jacklax

Member
They recommend having a test kit for anything that you add to your tank. Cal is a regular/standard addition, so it could really come in handy. Everything I've read shows that ph, dhk, and cal all have a direct affect on each other.
As to what dhk does...I can't say for sure (something to do with buffer capacity I believe)...I just know that it needs to be lower than what I have.
 

kimgpk

Member
I have an alkalinity test but it doesn't say dHk on it. Is it the same thing? But is this going to explain the brown problem that I have on my sbstrate?
 

jacklax

Member
Nope...I believe that alk (tests the hardness of the water) and dhk are 2 completely different tests. Someone with more experience can help us there. My test kit will test for both...
As to the brown stuff in your substrate...I think some of that is normal...but an idea of your nitrate/trite and phos levels could help to explain that even more. Here again...some more experience will certainly help as well.
 

reefnut

Active Member
Originally Posted by Jacklax
As to what dhk does...I can't say for sure (something to do with buffer capacity I believe)...I just know that it needs to be lower than what I have.
dkh is a measurement unit for alkalinity... alkalinity= carbonates and bicarbonates and sometimes borate. Yes it does effect the buffer capacity of the water or more correctly put, the ability to resist change in PH.
As important... alkalinity (carbonates and bicarbonates) is needed to form calcium carbonate. Calcium carbonate is what corals use to form their skeletons, it's what coralline algae uses to grow and spread. Basically live rock is nothing more than old coral skeletons or calcium carbonate from what used to be a coral.
 

saltfan

Active Member
Alkalinity has a direct affect on the ph ability to remain constant, so that it doesn't wonder to much. Adding one or the other does directly affect the others numbers. Buffer as you call it.
Man ReefNut is fast, I got to typing same time I guess...My bad Reef....
 
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