Reef Crystals Low Test Results vs. Label

[waltersreef]

Starting up a new tank and about to do first water change after cycling the tank. Decided to test my salt mix before adding it to the tank so I would know what I'm putting in. Based on the label, at 1.025 specific gravity and 79 degrees, the mix SHOULD give me about:

 

Mg 1285 ppm

Ca 435 ppm

 

But my test results at 1.025 and maybe a few degrees cooler are not even close:

 

Mg 1100 ppm

Ca 400 ppm

Alk 11 dKH

 

I'm never going to get to the levels I want if what I'm putting in doesn't even start at the promised levels. May have to 2-part dose the salt mix before it goes into the tank.

 

Anyone else have a similar experience? Found a few posts on other forums that sound the same. Are there salt mixes that are proven to mix up at the promised values?

 

[brandon429]

The measures posted will grow the system the same as if it tested accurate to the makeup claims

 

Also, if three different test kits give three different ranges that means don't concern too much about apparent mis levels

 

RC wasn't used in my tank untested for ten yrs it's good to go. I could switch back to it at any time from Kent and the system would grow the same corals though the levels truly differ

 

The alk above seems high but if this was my tank I wouldn't put stock into a single test reading not compared to another brand and RC lasted me bag to bag from 2001 to 2010 ish including whatever true alk ranges it has.

[waltersreef]

Thanks Brandon. I'm not too stressed about it since I'm setting this up as a macroalgae marine planted tank with probably just a few zoos. I'm guessing just regular weekly water changes will keep my levels where they need to be for my calcareous algae.

 

But still, just a bit disappointed in the lack of truth in advertising.

[Kayman]

Every time I test my Reef Crystals my magnesium levels are in the 1200s too, pretty annoying. I think my calcium is usually 400 or 420 and dKH is 10. Calcium and dKH are with API kits though.

 

I'm thinking about making a switch but for the cost it may not be worth it to me.

[squamptonbc]

I have over the last 7 months been comparing Red Sea and Salifert Calcium against API and API has thus far been just as accurate. I have tested a total of 3 API kits from different lots and its the same, I honestly don't think the pricier kits are worth it for Calcium.

 

 

 

Every time I test my Reef Crystals my magnesium levels are in the 1200s too, pretty annoying. I think my calcium is usually 400 or 420 and dKH is 10. Calcium and dKH are with API kits though.

I'm thinking about making a switch but for the cost it may not be worth it to me.

[waltersreef]

I've been toying with the idea of going to API also. But just for the basics like Nitrate and Phosphate. Something quick and simple to make sure everything is in check.

[Saltydude]

If your gonna have a marco and zoos tank I'm pretty sure you don't need to be concerned about magnesium, potassium, strontium and other complicated trace elements unless you have a sps dominant tank for softies and lps focus on alklinity and calcium.

I don't have experience with planted saltwater tanks but the plants will probbly need ferts... Ferts and corals dont go well eg. Reefers aim for 0 nitrates but plants need them to grow. Ect...

I don't know about zoos but leathers can do fine in planted conditions.

API brand kits work that's it. Their not the most accurate but accurate enough expect for sps tanks.

[Clown79]

I've compared api to other kits, i have seen no significant difference in results...only difference is price.

 

I always have issues with rc. My mag was constantly low and mixed low between 1100-1140.

 

Alk was 7-8

 

Ca 420