Alk low with a high Ph

[Sir Edward]

need some help with this one. I do a 50 gal water change once a month (was done two weeks ago). Before the water change my Alk was low and Ph high. After the change things were, well somewhat to the normal scale. I am back in the same situation, low Alk and high Ph. I have heard of using baking soda to correct, but . .I don't know. Help please . .

 

[dreaminmel]

There are a few articles here that should help you out. (I have this saved in my favorites. ) There is one for Alkalinity issues and also one about pH problems. And many, many others that are worth reading when time allows.

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=102605

 

[Conesus_Kid]

What are your numbers, specifically?

Tell us about your test kits, and if you're using a refractometer to measure salinity.

Are you dosing/supplementing anything?

 

[Sir Edward]

My Salinity is 1.022 on the Coralife Deep six. I have been using the Red Sea Marine Lab. The pH is 8.6, the Alk on the color chart is mostly yellow (low scale) The Calcium is 420, Nitrate is 2.5 and the Nitite is 0.05. This kit is almost used up and had asked earlier what kits everyone uses. I am ordering the Salifert test kits.

 

[Conesus_Kid]

Does the Alk test give a number?

Also, that salinity seems a bit low, but I wouldn't trust a hydrometer.

How are things in your tank? Do corals appear happy and healthy?

 

[pimpinitup6969]

+1 you should gradually bump your salinity up to around 1.025 over the course of a few days. You should also invest in a refractometer. They are much more accurate than a typical swing arm hydrometer.

 

[Sir Edward]

The Alk test is really a color chart with low range being 0 - 1.6 (low) 1.7 - 2.8 (normal) 2.9 - 3.6 (high). The color runs yellow (low) to blue. The test color is mostly yellow. I should add a refractometer with my PetSolutions order. I dose for Calcium and Strontium/Molybdenum.

 

[pimpinitup6969]

If you do order a refractometer make sure you get one with temperature correction.

 

[Gary Majchrzak]

okay.... I know that floating glass hydrometers need temp correcting but I never heard of a refractometer needing temp correction.

Edward- I wouldn't do ANYTHING until you get your S.G. up to 1.025-1.026.

After you get the specific gravity correct you'll need a better alkalinity test kit. Salifert is a good choice. You need real numbers and it will give you a value to work with.

Dosing Strontium/Molybdenum is not as nearly as useful as monitoring and dosing magnesium (if necessary) so there's another thing you can save money on.

 

[talon4x4]

okay.... I know that floating glass hydrometers need temp correcting but I never heard of a refractometer needing temp correction.

My refractometer has temperation compensation. Below is some info why it is important.

"Temperature is one of the single most important factors influencing accurate refractometer readings and is one of the largest sources of error in measurement. Refractive index is VERY dependent on temperature. It is well known that substantially all materials expand when heated (become less dense) and contract when cooled (become more dense). The speed of light in a liquid increases with temperature, and the refractive index, therefore, decreases.

The amount of error per degree Celsius is different for every fluid and differs for different concentrations of the same fluid.

Temperature compensation relieves the user of the responsibility to measure temperature and apply a correction factor when taking readings. Temperature Compensation Makes The Difference!"

 

[Sir Edward]

Ok, looks like I have some work to do. I will start to bring the salinity up today, just a bit at a time. I have also just placed my order for the new test kits as well as ordering Kent Tech M, magnesium.

 

[Sir Edward]

Something else to mention is my corals. While in the 72 bow, everything just looked really good with nice growth. Got my 220 running around Thanksgiving time. Everything started out good. But over these past six weeks or so, have noticed my corals look ok, but, no growth to speak of, with the polyps, I think they are even shrinking a bit.

 

[Gary Majchrzak]

My refractometer has temperation compensation. Below is some info why it is important.

"Temperature is one of the single most important factors influencing accurate refractometer readings and is one of the largest sources of error in measurement. Refractive index is VERY dependent on temperature. It is well known that substantially all materials expand when heated (become less dense) and contract when cooled (become more dense). The speed of light in a liquid increases with temperature, and the refractive index, therefore, decreases.

The amount of error per degree Celsius is different for every fluid and differs for different concentrations of the same fluid.

Temperature compensation relieves the user of the responsibility to measure temperature and apply a correction factor when taking readings. Temperature Compensation Makes The Difference!"

just a FYI:
if a refracto is calibrated at room temp and water samples are measured at room temp there's no need to pay extra for an auto temp compensation refracto. Ditto if calibrated at a higher temp but, realistically, a water sample consists of 3 or 4 drops of water so working with room temperature samples should pose no problem as long as your room temperature is constant.

 

[talon4x4]

just a FYI:
if a refracto is calibrated at room temp and water samples are measured at room temp there's no need to pay extra for an auto temp compensation refracto. Ditto if calibrated at a higher temp but, realistically, a water sample consists of 3 or 4 drops of water so working with room temperature samples should pose no problem as long as your room temperature is constant.

Good point. However, my tank is at 80 and when I do my testing I prefer not to wait around until that water temp reaches that of the house, which is usually around 70. And I paid $35 for my refracto with temperature compensation, which I thought was a great price. So its not like your paying much more for the convenience.

 

[Gary Majchrzak]

Good point. However, my tank is at 80 and when I do my testing I prefer not to wait around until that water temp reaches that of the house, which is usually around 70. And I paid $35 for my refracto with temperature compensation, which I thought was a great price. So its not like your paying much more for the convenience.

I agree. As a matter of fact, my refracto might have temp comp for all I know- it's not a feature that I looked for.

Realistically, though... as soon as you squeeze out 3 or 4 water droplets on a refracto they're at room temp within seconds. It's not anything like the (relatively) massive correction required with a glass float hydrometer (which can be extremely accurate as long as you perform temperature correction if necessary).