Reef Crystals - High Magnesium?

[muzikalmatt]

Lately I've been having issues with high magnesium in my tank (>1500). At first I thought it was the new test kit I was using (Aquaforest). However, I picked up a Salifert test kit and was getting the same readings. Given that I haven't been dosing magnesium, I figured it had to be my salt mix so I tested a fresh batch and sure enough it was reading off of the charts (>1500). Has anyone had issues with Reef Crystals mixing up with high magnesium levels? I bought a box and would hate to have to trash it all, but I certainly don't want to keep using it if this is a bad batch.

Also, if I have to buy new salt I'm considering switching as I'm getting tired of dealing with the residue Reef Crystals leaves behind. Any recommendations? I like to run my tank around 8.6 dKH, 400-450 ppm Calcium, and 1300-1400 ppm Mag.

 

[hllb]

Yes! I had a bucket that mixed up to 2400! My tank measurements of mg kept rising even though I wasn't dosing. I tested the fresh water multiple times and it was always around 2400. Crazy high. I still hover between 1500-1600 months later though I haven't tested my new salt for mag since it's not causing any noticeable issues right now.

I did not have any issues with reef crystals and residue, but I don't use a heater or mixing pump when I make water so that could have something to do with it. For those specs, you could use the salt I switched too, though it's pricey. HW Marinemix Reefer. There are lots of salts that target 8.5 dkh though, which is close to your target.

 

[muzikalmatt]

Thanks for the info and recommendation! I think you're right about the heat causing the residue to form when mixing Reef Crystals. I only tended to see it when I left the pump mixing too long causing the pump to heat up the water. I'll look into HW Marinemix and some other brands and see what fits me best. Odds are I'm going to have to toss this batch of salt mix. I'll probably try mixing another butcket just to make sure, but it sounds like that's my issue.

 

[hllb]

Definitely double check. It might be worth contacting the manufacturer if it tests higher than 1600. I didn’t because I paid so little from an amazon super sale

 

[reefiniteasy]

My tank has been running greater than 1500 the past month with no ill effects. Plenty of threads stating Mg that high is no problem at all.

 

[hllb]

My tank has been running greater than 1500 the past month with no ill effects. Plenty of threads stating Mg that high is no problem at all.

It can be an issue for snails if over 1600. And I was losing snails for no other discernible reason.

 

[muzikalmatt]

I've actually been wanting to run higher magnesium as I'd read that it can help with montipora growth and coloration, but I was hoping more for 1400-1500 ppm. The fact that I couldn't even measure it for a while since it was off the scale for the test kit had me concerned. I'm going to double-check a freshly mixed batch and see if I can figure out exactly what it's mixing up to. If it's only slightly over 1500 I may not abandon it since I'm only doing 10% weekly water changes, but with @hllb saying his was up at 2400 for him I'm concerned it may be mixing up much, much higher than 1500-1600.

 

[hllb]

I've actually been wanting to run higher magnesium as I'd read that it can help with montipora growth and coloration, but I was hoping more for 1400-1500 ppm. The fact that I couldn't even measure it for a while since it was off the scale for the test kit had me concerned. I'm going to double-check a freshly mixed batch and see if I can figure out exactly what it's mixing up to. If it's only slightly over 1500 I may not abandon it since I'm only doing 10% weekly water changes, but with @hllb saying his was up at 2400 for him I'm concerned it may be mixing up much, much higher than 1500-1600.

I just would refill the syringe with another .5 ml and then add on the appropriate amount to the 1500 top level.

I’m a woman, btw

 

[muzikalmatt]

I just would refill the syringe with another .5 ml and then add on the appropriate amount to the 1500 top level.

I’m a woman, btw

Whoops! My mistake! I will definitely give that a shot as I want to know what the actual levels are. I'll probably use both test kits to see what the results are as well. Thanks again for the help

 

[92Miata]

one thing to be careful of here, is that most magnesium tests seem to be much more sensitive (than say alk) and a much less clear titration border - so its possible to be stopping at the wrong point on multiple tests, and consistently be way off.

My Red Sea kit is probably .1ml from some-purple to all-purple, and .1ml is 200 ppm.

might be worth checking with Salifert to see what the proper end point is.

 

[muzikalmatt]

I had been using Salifert to test mag for the first year or so on my tank, but wanted to try a new test kit (Aquaforest) to see if it was easier to read. When I couldn't get a reading on the new kit I assumed the kit was the issue, so I bought another Salifert mag test kit since I was at least familiar with it. I was getting the same issue though: no color change, even after adding the entire 1 mL syringe of reagent.

One thing I haven't done yet is use the reference solution that came with the Aquaforest test kit. I could use that with both test kits to see how far off I am with my measurements, if at all. I truly think it's an issue with this batch of salt, but I'll do some more testing to make sure.

 

[hllb]

I had been using Salifert to test mag for the first year or so on my tank, but wanted to try a new test kit (Aquaforest) to see if it was easier to read. When I couldn't get a reading on the new kit I assumed the kit was the issue, so I bought another Salifert mag test kit since I was at least familiar with it. I was getting the same issue though: no color change, even after adding the entire 1 mL syringe of reagent.

One thing I haven't done yet is use the reference solution that came with the Aquaforest test kit. I could use that with both test kits to see how far off I am with my measurements, if at all. I truly think it's an issue with this batch of salt, but I'll do some more testing to make sure.

I too wondered if my Salifert was off so bought the aquaforest since BRS says it's the best. Tested almost identically to my Salifert test.

 

[92Miata]

One thing I haven't done yet is use the reference solution that came with the Aquaforest test kit. I could use that with both test kits to see how far off I am with my measurements, if at all. I truly think it's an issue with this batch of salt, but I'll do some more testing to make sure.

Its possible and maybe probable that it's a bad batch of salt. I just chucked out an old box of RC that was testing at 3 dkh (it was like 10 years old, so my fault here). Took me a whole bunch of time to figure that out.

Test the reference solution. It'll at least confirm you're using the test kits correctly - and then you'll know the salt is the issue.

While you're at it, it might not be a bad idea to get some calibration solution for your refractometer and make sure that's accurate. RC is supposed to mix up at like 1450 ppm at 1.025, so it doesn't take much error in a refractometer to be at >1500

 

[hllb]

Definitely calibrate the refractometer, though if ca and alk test as expected, that’s unlikely. I calibrate mine every month or two.

 

[muzikalmatt]

Thanks to both of you. I'll definitely check my refractometer. I'm using the Milwaukee digital refractometer so it's easy to calibrate. I'll follow up and let you know the results.

 

[hllb]

I'm still placing bets on the salt itself, based on my experience.

 

[muzikalmatt]

So Monday night I was able to do some testing. I calibrated my refractometer and tested the old batch of saltwater at a salinity of 1.026. I then tested the magnesium reference solution that came with the Aquaforest magnesium test kit using both the Aquaforest and Salifert magnesium test kits. The reference solution is stated to be 1310 ppm magnesium. The Aquaforest test registered it as 1370 ppm and the Salifert test came out to 1335 ppm, so pretty close for both tests.

I then tested the week old batch of Reef Crystals saltwater with both mag test kits. The Aquaforest results were 1500 ppm and the Salifert was 1450 ppm. So on the whole, both of these results were actually lower than I expected. However, I'm not sure if maybe the age of the saltwater had anything to do with it? Does magnesium dissipate as saltwater sits? I know I've seen the alkalinity drop if I let the saltwater sit for a few days, but I'm not sure if magnesium does.

I plan on mixing a fresh batch and testing it with both test kits and also retesting my tank and the old saltwater to see where things are. Overall, if the RC is mixing up around 1500 ppm I'd feel comfortable continuing to use it.

 

[Ike]

There's really not much to worry about unless you're above 1800-2000. Even higher, there don't seem to be any negative effects in my experience.

 

[lakai]

I used reef crystals to cycle my tank and while I switched salts, I still have high mag averaging 1460's. I've never had to dose mag

 

[Dom]

Lately I've been having issues with high magnesium in my tank (>1500). At first I thought it was the new test kit I was using (Aquaforest). However, I picked up a Salifert test kit and was getting the same readings. Given that I haven't been dosing magnesium, I figured it had to be my salt mix so I tested a fresh batch and sure enough it was reading off of the charts (>1500). Has anyone had issues with Reef Crystals mixing up with high magnesium levels? I bought a box and would hate to have to trash it all, but I certainly don't want to keep using it if this is a bad batch.

Also, if I have to buy new salt I'm considering switching as I'm getting tired of dealing with the residue Reef Crystals leaves behind. Any recommendations? I like to run my tank around 8.6 dKH, 400-450 ppm Calcium, and 1300-1400 ppm Mag.

I had a 200 gallon box of Reef Crystals that was only mixing to a dKH of 4.5. Turns out it was a bad batch of salt which BRS replaced at no charge.

The new box is mixing Mg levels over 1600. So I am beginning to feel that there is a quality control issue with Reef Crystals.