Dosing Ca/Alk/MG prior to Water change?

[King_Neptune]

Is it ok to dial in my water parameters before introducing it to my tank?
I typically get 450 ca, 6.5 alk, 1050mg just form mixing my saltwater.

would be nice to at least dial up my alk and mg before I introduce it to my tank.

 

[thatguy559]

thats how i do it

 

[eww]

That's what I do as well but since changing from standard IO to Reef Crystals I don't need to dose it up. It's pretty well there out of the bag .

 

[TJL]

+1 on pre-dosing std salt mixes

Todd

 

[King_Neptune]

I use reef crystals too. But it varies slightly sometimes.
Its coming out of my latest bucket:
470
6.5
1050
The problem with going from purple to orange is the orange is more inconsistent vs. the purple. Thx for the replies, Ill pre-dial from now on.

 

[jrgilles]

Still be careful about adding the Ca/Mg and Alk too close together. I did that a couple times many months ago, and all the Ca/Mg precipitated. I'm still getting flakes of it off the sides of my reservoir when I do water changes, and the mistake happened 8 or 9 months ago.

 

[cptbjorn]

you can dissolve precipitated carbonates in your saltwater mixing tank by adding seltzer water until the pH is slightly acidic. the excess co2 will blow off over a few hours/days depending on the air surface area and it is ready to use when the ph is back up in the 8's. you'll probably need to run an air stone if it is a mostly closed container though.

 

[jrgilles]

thanks cptbjorn. thats awesome.

Do you have a rough idea of how much seltzer to use?

Lets say I put in 18 gallons of R/O....

Maybe 3 or 4 2 liters of seltzer, and let it bubble for a few days, then add the salt and mix with powerhead as usual?

 

[King_Neptune]

Still be careful about adding the Ca/Mg and Alk too close together. I did that a couple times many months ago, and all the Ca/Mg precipitated. I'm still getting flakes of it off the sides of my reservoir when I do water changes, and the mistake happened 8 or 9 months ago.

Oops!
I dosed a couple ounces of MG and Alk within minutes of each other.
I know I have naturally high Ca so I wasn't planning on dosing that.

I was about to ask how long to wait before I can reliably test. Sounds like it can take upwards of a week to properly prepare water.

 

[cptbjorn]

Can you see inside the tank to know if it has dissolved? it is pretty tough to say how much because the carbonate that is on the walls should buffer the solution at 7.something until it is gone. I'd probably just try one two liter at first and see where it gets you, because how I've done it before has actually been yeast and sugar with the gas piped to an air stone instead of seltzer since that's what I had on hand. So I don't really know how much co2 I added.

Basically though I'd fill with RO, titrate with seltzer until the scaling is gone, add the salt mix and let it bubble until pH is correct. I don't know if you can let the co2 blow off before adding the salt mix though or else the calcium carbonate will just come right back out of solution I think.

 

[King_Neptune]

Can you see inside the tank to know if it has dissolved?
.

I already had it pre-mixed.
I use Bulk reef supplies 2 part dosing kits, so they are already dissolved in 1g jugs. I keep my water cold till the day before it goes in the tank, so its mixing with a power head cold right now. I put the dose in about 3 hours ago, when can I test to see how far its dialed?