Sky High KH/DKH
Printed From: Utah Reefs
Category: Specialized Discussion
Forum Name: Reef Chemistry
Forum Description: A place to discuss reef chemistry.
URL: http://www.utahreefs.com/forum/forum_posts.asp?TID=71029
Printed Date: August 22 2025 at 4:38am
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Topic: Sky High KH/DKH
Posted By: aporter360
Subject: Sky High KH/DKH
Date Posted: April 24 2014 at 8:32pm
| What are some of the side effects of a really high kh (14) and dkh (5). I know the best course of action is to let if fall and keep up on water changes, but it still continues to stay at 14 for the past month, I removed crushed coral and only have a bit in the tank now. Its a 10 gallon display with 10 gallon sump. Sump contains 200um filter, live sand from carib sea. some live rock.( will removing rock and watching for change in alk help at all?) a few pieces of crushed coral mixed in with sand(they are 1 in. pieces of coral not live when added-but became live very quickly due to high pore structure). diy skimmer. bare bottom display with only a few coral frags and fish in it. Will coral growth or coralline algae be affected? with this cause corals like zoas and palys to close up? |
Replies:
Posted By: LakeCityReefs
Date Posted: April 24 2014 at 9:01pm
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It's my understanding that alkalinity can be directly associated with PH. I had a nanotechnology setup for a few months and when I first started it the DKH read 12. It took about 6 weeks for it to settle at 9. The PH constantly read 8.2-8.3. I only had a few corals in it and a 6 line wrasse. The hammer and the mushrooms were good in the tank but I always had troubles with zoas opening all the way. Just my limited experience for what it's worth. |
Posted By: aporter360
Date Posted: April 24 2014 at 9:10pm
| good to know, without the aragonite my ph now reads around 8.4 and stays there |
Posted By: LakeCityReefs
Date Posted: April 24 2014 at 10:04pm
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I should also mention that my nano was a 6 gallon Fluval edge. I was doing a 1 gallon water change every week. I think that 8.4 PH is right at the top end of where you want to be. 8.1-8.4 I hope someone else chimes in with better advice. Let us know how it goes. |
Posted By: Dionysus
Date Posted: April 24 2014 at 10:11pm
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What salt are you using? ------------- AquaMedic 250 Watt XM 20k 2 420s Vhos 29 DT SPS Dominant 20 G Long Frag http://utahreefs.com/forum/forum_posts.asp?TID=56607&title=dionysus-tank-build" rel="nofollow - My Tank Progress =) |
Posted By: reefnfeef
Date Posted: April 24 2014 at 10:18pm
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How long has the tank been set up? ------------- aaaaaaaaaaaaaannd.... I'm broke |
Posted By: aporter360
Date Posted: April 24 2014 at 10:43pm
| Im using the standard instant ocean salt, and its been up for around 3+months now im gonna get rid of a piece of live rock to see if that is part of the problem and let them cure for a bit longer. |
Posted By: phys
Date Posted: April 25 2014 at 1:59am
| am i confused here or are you? KH is simply carbonate hardness while dKH is a measurment of it. Your dKH should be around 9 for hard corals and 7-8 for fish only systems. Ph is a bunk measurement. It changes throughout the day and can be affected by a lot of factors. I would not mess with any Ph buffers or anything to "fix" it unless you know what youre doin and why. |
Posted By: DLindquist
Date Posted: April 25 2014 at 6:10am
You believe your "uncured" rock may be the cause for high Alk? ------------- A government strong enough to give you everything you want, is powerful enough to take everything you have. |
pilotx44 wrote:Posted By: Mark Peterson
Date Posted: April 25 2014 at 7:52am
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Aloha Andrew, I agree with David and with Paul. Removing LR and LS is not the problem/solution and I would NEVER use chemicals to change pH in a reef tank. If Alkalinity is within range and gas exchange is good, pH will take care of itself. As a matter of fact it's the sand and rock that help keep Alkalinity (and pH) where it is supposed to be; 8-14 dKH. This range means that Alk can be at 14 and the tank will not suffer. A reading of 5 dKH is really low. I doubt that reading is correct, because in a new tank like this, Alk and Ca should be about the same as the salt mix. If I had that kind of Alk reading, I would first check my Ca level to see if it is out of range; 350-500 ppm. Then I would ask someone to check Alk and Ca for me to be sure I was testing correctly/getting the right measurements. I'll be doing tank maintenance in Sugarhouse today. Call me. I would be happy to stop in to see what's going on and check your Alk and Ca, no charge. Aloha, Mark  808-345-1049 call/text/visit anytime ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member 
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Posted By: aporter360
Date Posted: April 25 2014 at 1:26pm
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Thanks for all the help, I believe I accidentially switched kh and dkd numbers, just did a good 75 - 90% water change, letting tank settle and I will take all new measurements, then after a week or so I will post new measurements. Any help determining what could be causing changes would help a lot. I will start new thread with entire detailed description. Also removed most rock to make sure that's not leaching stuff. so we will see! thanks again Andrew |
Posted By: phys
Date Posted: April 25 2014 at 1:31pm
| the best thing to do is get a baseline of measurements. Do a measurement at the same time every day and track the changes. Then do it again after every water change or dosing or really any change to the system including adding corals. |
Posted By: aporter360
Date Posted: April 25 2014 at 1:44pm
that's what I plan on doing now again are there any concerns or side effects of a high alk like coralline algae not growing or corals not growing? cause I cant seen to grow coralline algae, and im trying to stay away from purple up.
also in my normal testing, every other measurement seemed to be good except alk so maybe I will find the solution now
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Posted By: LakeCityReefs
Date Posted: April 25 2014 at 2:13pm
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Make sure you have some rock with Coraline already on it. The more the better. This will seed it into your system. It tokeeps 6 weeks before I saw coral unexpected spots on my 55s glass but I had about 30 lbs of coraline covered rock to seed it. After 3 months it relay started growing on the pumps and everything else. DKH of 14 is pretty high but still seems OK. What I found is that if my DKH or Calcium was out of balance then I would see a lot of salt creep. I think that you want to aim for a balance of 10 DKH and 440 Calcium. Your Magnesium should settle around 1300-1350. |
Posted By: aporter360
Date Posted: April 25 2014 at 2:17pm
| Magnesium is something I haven't tested yet. I probably should get a kit but I don't have the money right now for another test kit. Especially the accurate ones that run quite pricey. Anyone have an extra for real cheap or willing to part with it? |
Posted By: Bryce
Date Posted: April 25 2014 at 3:25pm
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I wouldn't worry about testing mag in a 20 gallon system (maybe 15 gallon if you take into account your rock/sand/equipment water displacement), if you even do small water changes once a month your mag is going to be fine, if you have a lot of precipitation (white clouds/white build up on your equipment, especially equipment that gets hot), then I would think you would have low mag as thats a sign your alk and calc are binding together due to the low mag and you might want to test. DkH of 14 is too high in my opinion, especially in a low nutrient system but you didn't say your running a low nutrient system but I would target the 9-10 range as in my opinion while other ranges may be "ok" your on the fringe of safety so I shoot for the middle...the ocean is typically 7 dkh for what its worth.
------------- 65g Reef |
Posted By: sabeypets
Date Posted: April 26 2014 at 1:07am
Coraline algae usually takes around 6 months to start growing in a new system. From a chemical standpoint there exists an incompatibility between high dKH (alkalinity or buffer) levels and high calcium (Ca++) levels. Both cannot chemically co-exist. Whenever the dKH or alkalinity starts to rise, the calcium concentration will either go down or, you will have a very difficult time raising your calcium levels to the concentrations you want in your reef tank for good coral health (around 450 ppm ). If your dKH is presently too high (e.g. 12 or an even higher dKH) you can safely reduce it by performing SMALL water changes with water that has a lower dKH. Stability is one of the most important parameters in any saltwater system, changes must be made SLOWLY (unless its an emergency, heater stuck on water reads 93F, anemone went through power head and water is cloudy, ect.) ------------- Shaun American Fork "Would you leave a dead cat in your kitchen till tommorow?" Builderofdreams |
again are there any concerns or side effects of a high alk like coralline algae not growing or corals not growing? cause I cant seen to grow coralline algae, and im trying to stay away from purple up. also in my normal testing, every other measurement seemed to be good except alk so maybe I will find the solution nowPosted By: sabeypets
Date Posted: April 26 2014 at 1:11am
Carbonate hardness, or carbonate alkalinity is a measure of the http://en.wikipedia.org/wiki/Alkalinity" rel="nofollow - alkalinity of water caused by the presence of http://en.wikipedia.org/wiki/Carbonate" rel="nofollow - carbonate (CO2− 3) and http://en.wikipedia.org/wiki/Bicarbonate" rel="nofollow - bicarbonate (HCO− 3) http://en.wikipedia.org/wiki/Anions" rel="nofollow - anions . Carbonate hardness is usually expressed either as parts per million ( http://en.wikipedia.org/wiki/Parts_per_million" rel="nofollow - ppm or http://en.wikipedia.org/wiki/Gram_per_litre" rel="nofollow - mg/L ), or in degree KH (dKH) (from the German "Karbonathärte"). I'm confused also, a reading of KH (dKH) 14 is to high and KH (dKH) 5 is to low. ------------- Shaun American Fork "Would you leave a dead cat in your kitchen till tommorow?" Builderofdreams |
Posted By: aporter360
Date Posted: April 26 2014 at 6:42pm
| I will have a new post going soon giving a complete detailed description of my continuing problems, I realized I mixed up the numbers and the dkh and kh in this initial post. Great help though thanks. |
Posted By: JBlaze31
Date Posted: May 17 2014 at 7:22am
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I am also having the same problem. I have tested my alk twice in my tank as to try to establish a baseline of readings and am receiving the same kind of results. When I did my testing, I received a reading of dKH of 16 and 5.62 meq/L. Is that high or low or close to the money? If I am reading this thread correctly then my alk is lower than it should be. Could it be the test? I have the Red Sea testing kit that does PH, Alk, Ammonia, Nitrate, and Nitrite. Could the result cards be reading wrong? All of my other readings seem to be around the "normal" area. Ph is 8.2-8.3, Nitrates are reading around 3 and SG is 1.022. All I have in the tank right now is some live coral and sand to establish the bacteria needed for the pump and corals. Thanks in advance for the help.
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Posted By: Mark Peterson
Date Posted: May 17 2014 at 7:45am
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Aloha Andrew, If you are testing Alkalinity(Alk at 8-14 dKH/3-5 meqL is the suggested range), you should also be testing Calcium(Ca at 350-550 ppm is the suggested range). Are you using tap water or purified/Reverse Osmosis(RO) water? pilotx44, whose name is also Andrew , continued this thread here where he states that he found the reason for his tanks Alk testing at over 14dKH: http://utahreefs.com/forum/forum_posts.asp?TID=71160" rel="nofollow - http://utahreefs.com/forum/forum_posts.asp?TID=71160 Mark ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
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Posted By: JBlaze31
Date Posted: May 17 2014 at 7:57am
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I was not able to purchase the kit for testing Ca, so I have not been able to test that yet. I did fill the tank approx. 4 days ago with tap water with the buffer to assist in stabilization. I am starting to think, this is where I went wrong. I should have purchased a few gallons of the RO water that is sold around my area. I am still skeptical on that being the best move though. But it appears that is the way to fix my problem. So todays task is very simple, find some better water, and change some of it out. For a 75 gal tank, would 15 to 20 gallons be enough to make a difference? That is approx. a 20% water change. I am also sensing that it is not a good idea to attempt to put any types of corals in right now as well. At least until I get the alk figured out. ------------- 75G open canvas |
Posted By: Mark Peterson
Date Posted: May 17 2014 at 8:35am
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Good questions. It's nice to see a new person asking these questions so mistakes can be avoided. There is really no need to change the water now. In a couple months, use RO water for 10% monthly water changes. A 20% water change changes things by 20%, or less meaning Alk will go down, but not by much because the RO water mixed with salt will still have a dKH of 10. It's not like you are adding saltwater with a dKH of 0/zero. I wouldn't bother with changing water now. If you follow the method in the link below, you can have coral and fish within a week. I give away the live stuff you need to do it. Call/text me and come visit. Aloha 808-345-1049 750 E Lakepoint Dr. #4V Murray ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member
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