Is high carbonate hardness a problem?

[msn711]

My tank has recently finished cycling. My water parameters are:

 

Amm - 0

Nitrite - 0

Nitrate - 20

pH - 8.0

Calcium - 380

SG - 1.024

Temp - 79.5

KH - 14

 

As I understand it, KH is supposed to be between 7 and 11. Is this going to be a problem? And if so, what can I do to correct it?

[Maeda]

14 is a little high. Do a water change with softer water. If that doesn't work you're going to need an additive......

[msn711]

That's the other thing...I just did a water change. 5g on a 30g tank (about 40g when you include the sump). It read 14 after the water change...using instant ocean.

[Maeda]

check the kh of you tap

[MrAnderson]

Although the Ca/dKH ratio is unbalanced, it should be ok as long as your pH or temp doesn't go up.

 

That level of KH could become a problem if temp or pH goes up (and you should think about raising your pH from 8.0) because the Ca is way out of balance and a little low. Check your heater for abiotic precipitation (white stuff) and if you get any it will co-precipitate Ca in equimolar amounts, potentially crashing your Ca.

 

The ratio is so out of balance that I wonder what your Mg level is, and if your test kit is accurate - what brand are you using?

[msn711]

Maeda...I'm not using tap water. I'm using store bought RODI.

 

Mr. Anderson: How can I raise the pH without pushing the alkalinity any higher? I'm looking at an article from an old issue of reefkeeping that says that pH should be between 7.8 and 8.5, preferably 8.1 to 8.3, but that the lower levels are ok if the alkalinity and calcium are kept normal to high (~400-450ppm for calcium).

 

I'm not getting any abiotic preciptation thus far, and I'm using Kent's Liquid Calcium to try to raise the calcium before getting any corals. Well, that and waiting on the nitrates to come down.

 

I don't have a magnesium test kit. I'm using aquarium pharmaceuticals brand test kits...not salifert, I know, but I've never had a problem with them. The KH and Cal tests are brand new.

[MrAnderson]

Mr. Anderson: How can I raise the pH without pushing the alkalinity any higher? I'm looking at an article from an old issue of reefkeeping that says that pH should be between 7.8 and 8.5, preferably 8.1 to 8.3, but that the lower levels are ok if the alkalinity and calcium are kept normal to high (~400-450ppm for calcium).

 

But your Ca is low.

 

Hardness and pH are only related in that alk stabilizes a given pH, it doesn't necessarily change it. Hi alk doesn't always translate into a high pH, as your tank demonstrates. In a tank perfectly equilibrated with the atmosphere it does, but this is almost never the case in a home aquarium.

 

Alkalinity, aka carbonate hardness, is a measure of CO3- in solution.

 

pH is a measure of hydrogen ions in solution.

 

If you'd like to raise your pH, the easiest thing to do would be to lower CO2 by agitation or opening windows in your house/apt, and/or adding macroalgae.

 

This should achieve all your goals, lowering alk to reasonable levels, raising pH and allowing Ca to balance out.

 

http://reefkeeping.com/issues/2004-09/rhf/index.php

 

http://www.advancedaquarist.com/issues/may2002/chem.htm

 

http://reefkeeping.com/issues/2006-06/rhf/index.php

[msn711]

Thanks for the articles. I have added macro to the sump (chaeto), so hopefully that will help. The tank isn't near a window, and I have pretty good surface agitation. I'll keep an eye on things for a while. I won't be adding any corals into these paramaters level out anyway.

[horseflesh]

If you'd like to raise your pH, the easiest thing to do would be to lower CO2 by agitation or opening windows in your house/apt, and/or adding macroalgae.

 

 

 

And air pump can help too. I get +0.1-0.2 pH this way. YMMV.

 

 

 

But in the big picture, 14 isn't that bad. 7-11 is the recommended range, try to get there, but proceed slowly and don't sweat it being a little high. Like they say, nothing good happens fast in a reef tank.