High KH and GH

kyleflahardy

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Hi,
I have just discovered my general hardness (GH) in my tank is 180 or higher and my carbonated hardness (KH) is 240 or higher. What are the effects of these chemical levels being high and how can I lower them? Is there a chemical I can go out and buy? Thanks
 

ReeferMaddness843

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If so I'd recomend another form of testing for an accurate measurement. I'm also assuming this is in PPM. From my understanding so far in the hobby KH is what your needing to monitor and the GH is more of a freshwater based measurement. I personally have never tested GH, and honestly, don't even know where to start on that number. Let me do a quick conversion on your KH to dkh and I'll be right back. What are all your other parameters?
 
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kyleflahardy

kyleflahardy

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If so I'd recomend another form of testing for an accurate measurement. I'm also assuming this is in PPM. From my understanding so far in the hobby KH is what your needing to monitor and the GH is more of a freshwater based measurement. I personally have never tested GH, and honestly, don't even know where to start on that number. Let me do a quick conversion on your KH to dkh and I'll be right back. What are all your other parameters?
The scale on the back of the test goes from 0ppm to 240ppm
 

ReeferMaddness843

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Ive never dealt with strips as I've never trusted their accuracy. Id recomend getting another form of testing for the KH. I use salifert and love em. Testing method aside, what is the alk of newly mixed salt water you use? If your alk is lower in a new salt mix batch, you could opt for water changes to slowly lower that number. But not too fast. It's said no more than +\- 1dkh per 24hrs would be your best and safest method. What are your nutrients (NO3, PO4)? Also what are your Mag and Ca readings as all those numbers play a role in your alk indirectly?
 

Oceansize

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If we're talking fish and not coral, pH is more important than GH or KH, and so a high GH or KH may not be much to worry about as long as pH is in the proper range. ReeferMaddness is correct: GH isn't your concern as much as KH is. Proper KH is necessary for stable pH, however for the purpose of stabilizing pH, low KH is much worse than high KH and therefore you may not have anything to worry about.

If you do have coral, they will fix your high KH problem for you, as they will consume it and calcium over time.

Are you using tap water to make your salt water? If you're on the coast like me, your tap water could have very high GH/KH to begin with.

And yes, I'd recommend a different test kit for KH. I'm happy with API's reagent-based test, but not their strips.
 

ReeferMaddness843

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You'll really need to have an exact number on the KH in my opinion before making any drastic changes to make things "right"
@Oceansize is correct as well on tap holding high KH. I'm coastal as well. Anytime I run a test for Kh and go to rinse my vial, as soon as tap water hits it it goes back to the constant color before the color change.
 
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kyleflahardy

kyleflahardy

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Ive never dealt with strips as I've never trusted their accuracy. Id recomend getting another form of testing for the KH. I use salifert and love em. Testing method aside, what is the alk of newly mixed salt water you use? If your alk is lower in a new salt mix batch, you could opt for water changes to slowly lower that number. But not too fast. It's said no more than +\- 1dkh per 24hrs would be your best and safest method. What are your nutrients (NO3, PO4)? Also what are your Mag and Ca readings as all those numbers play a role in your alk indirectly?
I believe my tests strips are working fine. It gives an accurate readings on my PH, Nitrite, and Nitrates. (My PH is 8.2, my Nitrite is 0, and my Nitrates are around 5). I also do frequent water changes on my tank using store bought distilled water and sometimes RODI water from my LFS. I use the Instant Ocean Sea Salt. I don't think water changes seem to be having an effect on it, are there chemicals I can purchase to lower these levels?
 
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kyleflahardy

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If we're talking fish and not coral, pH is more important than GH or KH, and so a high GH or KH may not be much to worry about as long as pH is in the proper range. ReeferMaddness is correct: GH isn't your concern as much as KH is. Proper KH is necessary for stable pH, however for the purpose of stabilizing pH, low KH is much worse than high KH and therefore you may not have anything to worry about.

If you do have coral, they will fix your high KH problem for you, as they will consume it and calcium over time.

Are you using tap water to make your salt water? If you're on the coast like me, your tap water could have very high GH/KH to begin with.

And yes, I'd recommend a different test kit for KH. I'm happy with API's reagent-based test, but not their strips.
So I don't really have too much too worry about? This isn't endangering my fish right?
 

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Back in a moment. Got to get my kiddo some grub. I do not know of anything you can add to just drop the alk, and with those nutrients you may want to drop it a total of 3-6 dkh depending on what you're keeping. I run 0NO3 and 0PO4 with a 7dkh alk reading and works well for sps, LPS, and softies. Lower nutrients call for lower alk as well. I'm going to have to assume your Ca is low based on that number being so high and not dropping. Just fill me in with all the info of your system and I'll be back in a moment with how I would approach the situation. It's also a good idea to get the Kh reading on a fresh batch of salt mix.
 

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OP, is that your tank in your profile pic? You've gotten that far w/out ever testing for Calcium and you're still using test strips for KH? Color me impressed!

Oops, nm, saw your next post, lol.

But yeah, based on your tank description (fish-only with live rock, or FOWLR), I don't know that you need to worry about high KH as long as your pH is good and stable. Is pH on that little strip too? What does it say?
 
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kyleflahardy

kyleflahardy

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OP, is that your tank in your profile pic? You've gotten that far w/out ever testing for Calcium and you're still using test strips for KH? Color me impressed!

Oops, nm, saw your next post, lol.
I actually have two tanks. The one seen in the pic is the large one. The small one is having a problem with KH and GH and the large one is having problems with GH
 
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kyleflahardy

kyleflahardy

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OP, is that your tank in your profile pic? You've gotten that far w/out ever testing for Calcium and you're still using test strips for KH? Color me impressed!

Oops, nm, saw your next post, lol.

But yeah, based on your tank description (fish-only with live rock, or FOWLR), I don't know that you need to worry about high KH as long as your pH is good and stable. Is pH on that little strip too? What does it say?
And yes, my ph is also on test strips. Happy to hear that theres not much to worry about. Thanks for the help
 

Oceansize

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So I don't really have too much too worry about? This isn't endangering my fish right?

pH is what you're really worried about. If pH is where it should be and doesn't vary too much, then your KH is doing it's job and shouldn't be worried about. If you start adding corals/invertebrates then you'll have to be more on top of it testing-wise, not just good KH tests but Calcium and Magnesium as well. Until then, you're probably fine.

Again: are you using tap water to make your salt water? If so, that is very likely why your GH is so high.[/QUOTE]
 
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