Bizarre fresh saltwater parameters?

[TheStrangler]

Ahoy all, has anyone else ever just received a bad batch or batches of salt with strange parameters? I'm using Instant Ocean Reef Crystals buckets that have been rolled around on their sides recently to mix the salt. I don't test my mg/calcium/alkalinity that frequently as I don't have a very large uptake from corals. I don't dose anything but I do frequent water changes to replenish. I was doing a series of tests on my display tank and got an odd result with alkalinity showing at 5.8dkh with my hannah alk tester. I took out my red sea backup titration kit and tested and it came in the 6dkh range. The reagent was expiring this month so I ordered a replacement bottle and still reading 6dkh. I watched a video of the testing procedure to rule out errors in performing the test and still 6dkh. I tested a bucket of fresh mixed rodi saltwater and again right around 6dkh. I ran out of hannah reagent so I have more arriving tomorrow. At that point I thought that maybe my hannah salinity checker was off and that my salt was mixed under 1.026. Recalibrated that and used a spare hydrometer, nope. Calcium test read at about 450ppm and I haven't tested magnesium as I need more reagent but don't find magnesium testing all that useful normally.

I started manually dosing small amounts of sodium bicarbonate conservatively so that no harm would occur if Im getting some false readings from the tests, and after a day the red sea titration kit is reading 6.2dkh showing some positive movement. My pH is fine in the 8-8.2 range. Is there something I'm overlooking?

*edit* my Rodi filter has an inline tds meter and its reading 0s. By age its probably about time for me to change them, but my municipal water supply has pretty low tds so filters tend to last a lot longer than normal.

 

[Lavey29]

There were some reports of bad salt bags manufactured in turkey a few years back. Can't remember if it was instant ocean but I think maybe it was.

 

[TheStrangler]

Confirmed with both fresh red sea alk reagent and hannah checker that my fresh fixed water is coming up at ~6dkh I've been dosing sodium bicarbonate and have my alk up to about 8 now. I'm undecided on whether I throw the salt away or just keep using it but adjusting the alk up before doing waterchanges. Sort of a pain.

 

[gbroadbridge]

Confirmed with both fresh red sea alk reagent and hannah checker that my fresh fixed water is coming up at ~6dkh I've been dosing sodium bicarbonate and have my alk up to about 8 now. I'm undecided on whether I throw the salt away or just keep using it but adjusting the alk up before doing waterchanges. Sort of a pain.

It sounds possible that you have a batch with low Alk.

I'd simply add baking soda to bring it up if other parameters seem correct.

 

[TangerineSpeedo]

I don't want to be a broken record and say "you get what you pay for" but there is a reason there is a price difference. Yes, there are major players that use IO and RC, but they test the mix before using. Just the fact that you knew to roll the bucket to make sure things were mixed is telling. Don't get me wrong, it will do the job, 99% of the time quite well, but there is a but... The amount of salt that IO, now Spectrum brands, sells is crazy, so yes you may have a few buckets that show up missing a few elements. The best way is to do an ICP test on a new bucket of salt ( which is counter productive if your buying the salt because it is cheap) or purchase salt that already has a batch ICP test. At the very least you should test the big three and see what, if any adjustments need to be made.
I really do not want to hear all the "I have been using for years and never had a problem" Well, consider yourself fortunate.

This is my opinion and does not necessarily reflect the opinion, stated or otherwise, of the powers the be....

 

[TheStrangler]

I don't buy Instant ocean because its cheap, I buy it because from my past experience its the most consistent due to its massive batches and market share. Over the past decade I've seen question after question about what's the best salt, and the general consensus is that it doesn't hugely matter besides what the parameters you're targeting that the salt provides. I've seen again and again that its not a few bucks cheaper because its inferior to any other salt, its a few bucks cheaper due to economy of scale. All salts will stratify if they're left to sit for extended periods of time, so you should always roll any mix you have around occasionally. I've heard the occasional story about of a bad batch of salt, but it normally concludes with API test kits or an out of whack refractometer so I was just curious if there was something I was overlooking.

 

[Randy Holmes-Farley]

Could be a bad batch, a batch with precipitated calcium carbonate in it, perhaps due to moisture getting in, or forming when the salt was added to water, or a batch that is still inhomogeneous.

If a bad batch, it is likely we will start to see more reports.

In any case, the sodium bicarbonate additions seems an appropriate plan.