High KH and GH

[kyleflahardy]

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]
Nope rodi or distilled only

 

[Oceansize]

Nope rodi or distilled only[/QUOTE]

Hmm then I wonder if your KH is really that high after all. ReeferMaddness may be correct in his original suggestion: testing error. Just because the strip works well for some things does not mean it works well for all things. Strips are notoriously unreliable, they're probably better for detecting relative changes than absolute levels. (i.e. they can accurately tell you if a certain parameter is going up or down based on several tests over days, but they probably can't accurately tell you exactly what those levels are)

 

[ReeferMaddness843]

Id say the GH is irrelevant as I've never heard much convo or dealt with it based on my experience. If it's a fowlr, then I wouldn't even sweat that. @Oceansize is correct tho, if you opt to add corals later, definitely monitor those parameters mentioned at the least. I strongly urge another test method if start to go that route. I've not heard nor experienced anything good of strips even in my freshwater days.

 

[Rick.45cal]

You need to test Alkalinity via a Carbonate Hardness test. I use a Hanna alkalinity checker, and a Salifert KH Carbonate Hardness test kit as a backup.

 

[melypr1985]

You've gotten great advice here. I agree. GH is useless in saltwater. KH should be measured using a better kit like Salifert, Redsea, or even API liquid kit would be better than the strips. I suggest getting a better kit to test with, get a real number in dkh and go from there. Of course this is only needed if you are keeping corals or anemones... something of that nature. With fish only, it's not all that important.

 

[BiggieJohn]

measuring GH in a saltwater tank is almost completely meaningless. It is a total of KH + Magnesium (Mg) +Chloride (Cl) + Sodium (Na) +Sulphur (S) +Potassium (K). Since we have huge amounts of sodium, chloride and magnesium, as well as elevated carbonate in saltwater, the number will always be very high. In freshwater aquariums, they compare GH and KH to get an idea of mineral content of the water that is not from carbonate since they dont have the salt component. Also, the API test strips are generally considered pretty bad. The ones from Tetra (also sold by marineland) are better, but liquid tests are always better for saltwater tanks.

 

[Randy Holmes-Farley Verified Community Expert]

GH is nearly meaningless and ALWAYS is super high in seawater. Never bother measuring it.

Just to clarify, GH is the combination of calcium, magnesium, strontium, and a few very low level ions such as barium (it does not include sodium, chloride, sulfate, carbonate, bicarbonate, potassium, etc.). The units of measure take a chemist to disentangle in seawater.

 

[lowellb]

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.

I have had a good response from the api strips. I use the reef test kit and the strips have been right on the money, especially the PH part of the strip.