Alk Low after mixing salt

[chrisjj625]

So I have been using HW salt mix and BRS says it should mix up to 9 dkh. My tank doesn’t match that so I decided to test a fresh mix of saltwater and got 7.3 dk. Testing was done with sailfert test kits. My question is can alk be precipitating out? I typically start my mix 24 hours in advance. Is this too long?

 

[Randy Holmes-Farley]

If it was precipitating (which is normal), you would see white precipitate on the sides or bottom.

In any case, it seems fine to use.

 

[chrisjj625]

I don’t really see anything precipitating out. How can I get the dkh closer to what it’s supposed to be? Mix it less?

 

[Randy Holmes-Farley]

I don’t really see anything precipitating out. How can I get the dkh closer to what it’s supposed to be? Mix it less?

"Supposed to be" is not exact by any means for many reasons. Maybe you made it up to a lower salinity. Maybe the bag has settled. Maybe the batch is low. Maybe your alk measurement is off a bit. Maybe BRS made any or all of these "mistakes". Maybe it is a mixture of many of these explanations. Do not be over confident in any of your measurements, or those of others.

If you do not see any precipitate, then it isn't from precipitation.

Just add baking soda if you want the alkalinity higher at the salinity you are using.

 

[chrisjj625]

Should I just aim to keep it consistent then instead of chasing what it “should” be or does the salt mix suck. Lol I guess I would just like to be able to repeat I reputable source.

 

[Randy Holmes-Farley]

Should I just aim to keep it consistent then instead of chasing what it “should” be or does the salt mix suck. Lol I guess I would just like to be able to repeat I reputable source.

It doesn't matter what the mix should be . It matters what you want the tank to be. 9 dKH is fine. So is 7 dKH. You'll find reefers that target both, or any number in between. I generally recommend 7-11 dKH, unless it is a low nutrient system where I would run over 8 dKH.

 

[Tamberav]

If it was precipitating (which is normal), you would see white precipitate on the sides or bottom.

In any case, it seems fine to use.

I just mixed up some salt and even though it was a NEW bag, it was a block (but easy to break up with my hands, not a SOLID block). It precipitated I guess due to this as I can see the white floating around. Alk is 5.4, have not tested Ca or Mg yet.

Can I just add some BRS 2 part solution to bring it up to around 7 and then use it? Maybe pump it through a sock to catch the precipitate?

Should not cause any harm? It is Instant Ocean salt. Throwing away 200 gallons seems silly.

Thanks!

 

[Randy Holmes-Farley]

That's a fine plan. I'd add only the alk part. You can correct calcium in the tank if there is any concern.

 

[Tamberav]

That's a fine plan. I'd add only the alk part. You can correct calcium in the tank if there is any concern.

Thank you! I ended up doing a 80% water change on SPS 5g pico after correcting the levels (and filtering out the precipitation) and there was no negative effects at all!