dose directly to replacement water?

[Mavrk]

When I mix saltwater, my calcium is a little lower than I would like. Is it better to dose the replacement water directly or dose the whole tank after the water change? I have been doing the latter since I figure it would be better to put a few teaspoons into 80 gallons of water than into 8 gallons. But I thought I would see what others do.

 

[seapug]

A few teaspoons of what? Method and amount depends on what you are using.

 

[Mavrk]

ESV B-Ionic Original Ca Buffer Part 2 (Calcium). According to the calculator I need 3 tsp (15 ml) to bring my 8 gallons of newly mixed water up 30 ppm. I have always figured that it is perfectly safe to add this amount to 80 gallons of water, but then my newly mixed water doesn't have any livestock so it shouldn't matter.

 

[The Professor]

I am no scientist but I do the same thing. I also use ESV. Through my tests of IO reef crystals it has a slightly low calcium reading as well as magnesium. I just dose it to bring it up with display tank levels. I have noticed no ill effects.

 

[rbursek]

ditto

 

[atvdave]

If your just trying to correct the replacement water's CA then just put it in the replacement water first.

However if the correction is for the total tank size then you will need to put in in your tank, a high flow area if you can.

If you put to much of the CA supplement into a small portion of make-up water then it may cause precipitation & could drive down other parts of the water like ALK.

 

[Randy Holmes-Farley]

In general, if you are trying to boost the tank, then dose the tank.

But, tt is fine to boost new salt with as necessary to make it match your goals, and the calcium and magnesium in it might be boosted a little bit more to help raise the tank if necessary (say, 550 ppm max for calcium), but do not try to boost the alkalinity in the new salt water in a way that takes it above 11 dKH (4 meq/L) as you will risk precipitating calcium carbonate from it.

FWIW, I boost my Instant Ocean with calcium via Dowflake and magnesium via MAG flake, both of which are available from hardware stores.