water parameters

[Reef_Obsessed]

Hi guys and gals,

I have a 20G with fish and mixed coral tank. I was testing my parameters today and here is what I came up with:

PH - 8.1
Temp 81*
Alk - 3.5 meq
Cal - 480
Magnesium - 1230
Phosphates - 0
Nitrate - 0
Ammonia - 0

I was just wondering why the high calcium and low magnesium? Should I dose magnesium at this point? Is the high calcium a problem?

About Phosphates: An employee at a LFS told me that I should have a little phosphate in the water to strengthen LPS skeletons...is this true? or just another LFS story?

 

[Randy Holmes-Farley Verified Community Expert]

Phosphate is a useful (required) nutrient at some level, but it does not strengthen skeletons. 0 phosphate is a vague concept. Some kits read zero even when there is plenty because the just cannot read low enough. Plenty is typically 0.02-0.03 ppm or so. Can your kit read that low?

Unless you are dosing, the values you have for calcium and magnesium will reflect the salt mix and/or the accuracy of the kits you are using.

 

[Reef_Obsessed]

Phosphate is a useful (required) nutrient at some level, but it does not strengthen skeletons. 0 phosphate is a vague concept. Some kits read zero even when there is plenty because the just cannot read low enough. Plenty is typically 0.02-0.03 ppm or so. Can your kit read that low?

I am using the typical API Phosphate test that measures by 1/4 ppms, such as 0.0ppm, 0.25ppm., and 0.5 ppm. My test was reading 0.0 ppm. The test kit shows an expiration date of 6/2016. When I mentioned that I use distilled water, the LFS guy says, "oh, that may be why you are not showing any phosphates!" Any truth to this you think?

Unless you are dosing, the values you have for calcium and magnesium will reflect the salt mix and/or the accuracy of the kits you are using.

I have not been dosing anything! Do you think I should carefully dose magnesium? I would like to, at least, get my level up to 1280

 

[Randy Holmes-Farley Verified Community Expert]

No, the distilled water comment is uninformed. At the scale of your kit, 0 ppm phosphate is by far the best result.

 

[Reef_Obsessed]

No, the DI water comment is uninformed. At the scale of your kit, 0 ppm phosphate is by far the best result.

It's so crazy how these people can just look at you with such certainty and tell you they know what the problem is, without really knowing!

 

[Randy Holmes-Farley Verified Community Expert]

I have not been dosing anything! Do you think I should carefully dose magnesium? I would like to, at least, get my level up to 1280

What salt and what salinity? If the salinity is low, just raising it will boost the magnesium.

 

[Randy Holmes-Farley Verified Community Expert]

It's so crazy how these people can just look at you with such certainty and tell you they know what the problem is, without really knowing!

Yes, and they usually have a product that will "fix" it.

 

[Reef_Obsessed]

What salt and what salinity? If the salinity is low, just raising it will boost the magnesium.

I use Coralife salt and my salinity is right between 1.025-1.026

 

[Reef_Obsessed]

Funny, right after I posted the type of salt I use, I received my delivery of Coralife salt and right on the back, it states that Coralife holds a magnesium level of 1110-1250ppm...I think I found the issue!

But that does not solve the high calcium, since Coralife salt holds Calcium levels of 390-410 and my API test was reading 480ppm. Fortunately, with that package, I also received a Salifert Calcium test, so I will be checking the accuracy very shortly and my first refractometer so I can double-check the salinity as well. Man, I'm starting to feel like a real-life chemist, lol

 

[Randy Holmes-Farley Verified Community Expert]

Is it lower now? It used to have calcium above 500 ppm at 35 ppt (1.0264).

 

[Reef_Obsessed]

Read with the new refractometer, salinity at 1.028...easily fixed, but the calcium level is really confusing me...

I did the calcium test with the new Salifert test and it is off the chart. I emptied the syringe of solution and still no change in color, so I added a little more to see how long it would take to change and it was at least 3-4 more drops, which is suggesting a calcium level of 550 ppm? Is it possible to be that high? and if so, is that dangerous to the fish and coral?

 

[Randy Holmes-Farley Verified Community Expert]

Read with the new refractometer, salinity at 1.028...easily fixed, but the calcium level is really confusing me...

I did the calcium test with the new Salifert test and it is off the chart. I emptied the syringe of solution and still no change in color, so I added a little more to see how long it would take to change and it was at least 3-4 more drops, which is suggesting a calcium level of 550 ppm? Is it possible to be that high? and if so, is that dangerous to the fish and coral?

550 ppm calcium in seawater is not a big problem and many tanks run that high. If you drop the sg from 1.028 to 1.026 the calcium will also drop from 550 pm to 510 ppm.