Old salt mix vs old salty reefer

[jbaur13]

Hello. I bought way too much salt around 5yrs ago. I fell very behind in maintenance and as a result it sat. I'm sure as you know, that stuff has become pretty expensive. At this point my tank is fish only... I've been slowly bringing all my parameters up to be ready for corals.

I'm using instant ocean. They've basically become a 20lb bag of bricks. It tests very low with mg and ca out of the bag (1100mg and 260ca), so I've been adding those both to my tank and mix. Alk is 8.7dkh, which I haven't felt the need to mess with.

When they mix I get a good deal of precipitation... a white dust over everything. I'm assuming that's the ca and mg that has become stale.

Speaking from experience, are there any concerns with continuing to use an old salt mix and adding ca/mg to bring it up to reef parameters?

Do you know of anyone who's ever lost fish or corals that can only be explained as from using old salt?

 

[Jposch]

My guess is you'll wind up with very high sodium and chloride levels if you exclusively use that salt back to back. You could gwt away with maybe using it every other water change.
The calcium and magnesium are precipitating out as carbonates and leaving the sodium and chloride behind. You then add more with your supplements and ir won't be getting diluted out. Probably fine for fish, but likely an issue with coral over time. At 35ppt, your alk should show about 11dkh or so with purple IO saltmix.

 

[griss]

I agree with Jposch.

A little tip if you have a Petco or PetSmart near you. They will match their online sales price in the stores.

My local Petco has a bucket listed at $79.99. But show them their online price of $51.50 and they’ll match it.

https://www.petco.com/shop/en/petcostore/product/instant-ocean-aquarium-salt

 

[Jposch]

Chewy often has sales, and you can compound discounts by signing up for scheduled shipments, but then cancel it as soon as the salt ships. They go by email addresses, so easy to just go through a bunch of burner emails.
Alternatively, aquaforest salt is pretty cheap for the fish only mix.
@jbaur13 if tou live somewhere cold, I'd use that old, bricked up saltmix for melting ice on the sidewalk.