Salt Mix Question - Not what you think

[pdiehm]

If I understand correctly, we want to mix up our salt batches at:

Salinity: 1.024 - 1.026
Alkalinity: 8-12 dKH
Calcium: 380-450
Magnesium: 1200-1400
Temperature: 76-80

For my salt, I think due to how easy it is to get, I'm going to use IO Reef Crystals. I was going to use Red Sea Coral Pro, but it's only available mail order around here. Not overly convenient. But I digress.

According to That Pet Place Salt Mix Guide, Reef Crystals mixes up at (1.026 SG):

Alkalinity: 13 dKH
Calcium: 490
Magnesium: 1440

Which leads me to my questions. My first batch of saltwater that i initially put in the tank, will be based on how many gallons I actually need (empty tank is 120 gallons, but Rock, Sand and Overflow box will reduce that number). The water going into the tank will be at 1.026, 13 dKH, 490, 1440.

All of these numbers are too high. Will they fall over time?

If I'm making new water for a 10% water change every week (or 20% every 2 weeks), and I want to maintain consistency, if the alkalinity and such does fall and it's at say 10, and I add 20 gallons of 13 dKH water...will that cause too big of a swing?

One of the reasons I am thinking about doing small weekly water changes is because A) I don't want to dose and B) Not set up to do automatic dosing...so I figure small water changes will keep the numbers consistent. Is that an accurate assumption?

What I plan to stock is fish, and some very very beginner, easy to care for, hard to kill corals. Not sure what everyone calls them, but that's what I'm calling them

 

[zesty]

I think you are on the correct path. The one thing is I would never take the word of what something mixes up. Always do the testing yourself. It's just the failsafe way of knowing what's going in your tank.

They will fall, and at first, slowly. Not until you get a large amount of corals that need to build a stony skeleton that you need to concern yourself with dosing. Water changes will be perfect for what you're doing.

As for beginner corals, zoas, leathers, mushrooms are great for the beginner. Very forgiving.
Here are some other suggestions
Beginner Corals: Corals Suitable for Beginners in Saltwater Aquariums

 

[pdiehm]

Thanks. I'll never have a large amount of corals. Just 5-7 that add some color and movement behind the fish. That's why I think that I may be overthinking it

 

[Randy Holmes-Farley Verified Community Expert]

The alkalinity will fall over time. Calcium will very slowly fall, and magnesium will hardly fall at all in your tank.

I think it is a fine plan to not dose anything (at least at first) and only monitor alkalinity. If it does not get too low, then there is nothing else you need to dose.

 

[pdiehm]

No issues with Reef Crystals?

I toyed with Red Sea Salt (not the Coral Pro) as the numbers listed appear to be where most people want them, albeit on the low side. But the availability factor played a huge part in deciding that I'll try Reef Crystals.

 

[Randy Holmes-Farley Verified Community Expert]

No, there is no problem with Reef Crystals.

It and Instant Ocean are among the two most popular salts for reefs, and while the alk is high, it won't be a problem in your tank and the other values are fine.