PO`d at salt mix
 

So this is the second time in a row that I made a salt mix from IO salt and my mg and ca have been crazy low. I just started a new box too. When I measured my mix my mg was 1120 and my ca is 360 but alk is 10.1. I just got a refractor which is reading totally different from my hydrometer so now I question which is right. For a 15 gallon mix, I added about 8 cups of salt which reads 1.026 on my refractor. To me this seems like not enough salt compared to what I used to use. How much salt are you using compared to water volumeÉ

If properly calibrated, your refractometer will be much more accurate every time.

I think IO advertises as 1/2 cup per gallon to get a 1.026 salinity.

If you're using good filtered water, you're readings shouldn't change that much.

If you use tapwater or your filter cartirdges are getting older, you will see some of the magnesium and other trace elements in the source water elevate your levels.

from the website

Q: After dissolving Instant Ocean® in purified water, my calcium and/or magnesium concentration seems lower than expected. Why?

A: Instant Ocean® is formulated to provide a solution with levels of calcium and magnesium found in natural seawater (NSW), assuming you use purified water to dissolve the sea salt. Tap water most often contains dissolved calcium, magnesium and other minerals that will add to the levels provided by Instant Ocean®. The specific gravity of NSW is typically 1.026 (35 parts per thousand, or ppt, salinity). When dissolved in pure water to a specific gravity of 1.026, Instant Ocean® should provide a solution that has 400 mg/L calcium ion and 1320 mg/L magnesium ion. If Instant Ocean® is dissolved to a lower specific gravity, then these concentrations (and, in fact, the concentration of every other ion) will be proportionately lower.

Thanks for that. I guess that before I was using more salt because my hydrometer was so off that my levels of mg and ca were a lot higher when I was doing the mix before. The last time I did a mix though the mg was 870 but I was a the bottom of the bucket and I guess I should have mixed the salt up more.

I've never mixed my io while in bucket mg is usually in the 1100-1200 calcium is 360-380 that's why it's cheaper in my opinion it more for fowler tanks or people running a calcium reactor I add both mag chloride and calcium chloride to bump it up where it belongs. A refractometer is much more accurate but sounds like you may wanna calibrate yours.

Welcome to Instant Ocean salt and hydrometers. Your experience is typical of the vast majority of users. Do a search and you'll see that everything is normal and there is nothing to get upset about.

Most mass produced sales are the same as far as this goes.

IO is just so widely used that you hear about it a lot more.

Whatever happened to that thread on RC that tracked this?

I'm happy enough with IO.

I use roughly 1300ml to mix 10g. If you want to be more precise, I use 128.81ml/g
This gives me 1.026 everytime. But thats my measuring cup and gallon measurements.

Sure it's big 3 params are a bit off, but I adjust/dose the new water before adding it to my DT. Usually I need to turn my alk pump down for a week as well.

The last few buckets have given me;
Alk 10.5
Ca 380-400
Mag 1380-1400+
This latest bucket is still 1300+ mag.

Yup, mag from IO has been high lately, but it saves dosing :smile:

IO is 1/2 the price of the other salts whose params still need adjusting.
Id be surprised if IO cost me $5 a pail in bulk chems to adjust to "target numbers". Im going to figure this out now that Ive thought about it