RedSea 4 part issue with Alkalinity, undissolved in bottle

[TScarin]

Anybody have this issue with the 4-part program "alk" bottle? I began using this program at the beginning of 2025. First 2 months it was great, kept Alkalinity around 9.5. When the first 4 bottles ran out, I replaced with a fresh batch of new bottles. After a week I noticed my alk had dropped to 7. I discovered the dosing tube had hard crystals in it, blocking the flow. I poured out the contents of the "part 2 / alk" bottle to discover a brick at the bottom of it, basically undissolved minerals of whatever they use in this. I saw no instructions about making sure to shake these bottles prior to using. I was under the impression everything was plug-and-play right of the box. So just a head's up if you decide to use it.

 

[Randy Holmes-Farley Verified Community Expert]

The alk part of two part systems is typically close to saturation (except for ultra high pH versions using sodium hydroxide), and that limits the potency.

If it gets cool, during shipping or at home, it can precipitate solids.

Warming to redissolve can often solve it, but adding water can also be done (recognizing a potency decline).

 

[TScarin]

The alk part of two part systems is typically close to saturation (except for ultra high pH versions using sodium hydroxide), and that limits the potency.

If it gets cool, during shipping or at home, it can precipitate solids.

Warming to redissolve can often solve it, but adding water can also be done (recognizing a potency decline).

That seems to be the consensus / likely cause of this. These bottles were shipped in December via UPS, probably travelled through cold climates and sat outside my house in the cold for a few hours when they were delivered. Thanks for the response.

 

[Randy Holmes-Farley Verified Community Expert]

That seems to be the consensus / likely cause of this. These bottles were shipped in December via UPS, probably travelled through cold climates and sat outside my house in the cold for a few hours when they were delivered. Thanks for the response.

You're welcome.

Let us know if warming solves it. :)

 

[TScarin]

You're welcome.

Let us know if warming solves it. :)

I tried it on a new, unopened bottle that felt like it had a brick at the bottom. Definitely broke up the brick after sitting in a hot water bath and giving it a shake. But with the RedSea bottles, it's so hard to tell if it all got dissolved since they are opaque and have no "window" on them to see the contents. When it comes time to use this one, I will definitely dump it out into another container to verify.