Freshly mixed Instant Ocean testing calcium at 800?

[gobble]

I don't test calcium that often and my tank tested around 800 last week with the Red Sea kit. I then tested my water storage tank and same thing. It also tests around 800.

I figured the test kit must be wrong even though not expired so I ordered a Salifert kit. Same thing, both test around 800. I then tried my RODI water and the starting point is the endpoint color, so no calcium in the RODI water.

Has anyone ever seen this with Instant Ocean mixed at 35 PPT?

 

[dadnjesse]

Are you sure your salinity is what you think, is alkalinity also testing high?

 

[gobble]

Salinity is 35 on the just calibrated refractometer, 34 on the just calibrated Hanna and 34.7 on my Apex last calibrated a couple months ago. I doubt salinity is the issue.

Alkalinity is around 8.5.

 

[Potatohead]

RHF would know better than I but I don't even think it's possible to have calcium that high, it starts to precip out I think in the high 500's or so

 

[Flippers4pups]

I don't test calcium that often and my tank tested around 800 last week with the Red Sea kit. I then tested my water storage tank and same thing. It also tests around 800.

I figured the test kit must be wrong even though not expired so I ordered a Salifert kit. Same thing, both test around 800. I then tried my RODI water and the starting point is the endpoint color, so no calcium in the RODI water.

Has anyone ever seen this with Instant Ocean mixed at 35 PPT?

I've not seen it that high at all. Ive used it for decades. What others have said, what's your alkalinity at?

 

[lapin]

It would be interested to see your Ph, alk, mag numbers on that mix and your tank

 

[gobble]

Just tested the instant ocean with Salifert kits and the Hanna salinity meter.

Salinity = only 32...
ph = 8.0
Alk = 8.6

 

[lapin]

If your tank has the same alk and ph numbers I would expect your pumps and other things in your tank to be coated with precip. with calcium at 800ppm
Are you dosing kalk or something?

 

[Randy Holmes-Farley Verified Community Expert]

How large is the tank and how large of a batch did you make? Sometimes the bucket can settle and become in home generous.

still might also be test error or a bad batch

calcium can be 800 ppm. With regards to precipitation from NSW, it would be the same as 14 dKH for alk or pH at 8.5

 

[gobble]

My mixing tank is 65 gallons and display is 200. I had made a 60 gallon batch with 20 gallons left.

I just put that 20 gallons into buckets and am making RODI water for a new batch right now. The plan is to dump a 50 gallon bag of salt into 50 gallons of water and see what I get.

 

[Randy Holmes-Farley Verified Community Expert]

I now even more strongly suspect an error of some sort. To get the whole tank to 800 ppm calcium matching the new water would require many buckets to be off to the same extent.

 

[gobble]

If it matters my Hanna tester was measuring alkalinity 1 dkh low compared to my new Alkatronic so I bought both Red Sea and Salifert kits to compare. Hanna was around 1 dkh lower than all of them. I had been dosing alk to around 9.5 (after error) and calcium to match for months.

Earlier this year I bought a new Red Sea calcium kit because my old one went out of date, and the calcium number shot off the chart with the new kit. I went without dosing calcium for some time to bring the number down to 420 according to the new kit.

I know it sounds like I must not know how to test or calibrate, but I'm confident in my methods. Maybe I'll run a sample to the store later.

 

[gobble]

My fresh 60 gallon batch of Instant Ocean measures 475 calcium. I have some of my old batch in 5 gal buckets and the calcium is so high I get no color change with the first 1ml syringe of part C. Same salinity.

I measured my tank again and get around 800 calcium. It takes 1.7ml of part C to get a color change.

Very strange. I did each test twice and get consistent results.