Dosing combined with auto topoff?

[smspring]

I have a 30 gallon bucket I use for fresh water auto topoffs. Is it ok to add Mg, Alk, calcium, etc... supplements directly to the auto topoff water? Is there any concern about mixing supplements this way? Tips and tricks?

 

[knutrainer]

The only potential problems I can think of would be if you have a variable evaporation rate it could throw things off but I'm no dosing expert. Need more input from others.

 

[Darth_Tater]

I would also be worried about getting a high enough concentration to keep up with your needs without anything precipitating (which takes it out of solution and makes it useless). That depends though on how much water you're adding and how much you need to dose daily.

Even if this isn't a concern you won't be able to get consistency unless you are artificially controlling the humidity in the room the tank and sump are in, as knutrainer mentioned.

Edit: I hate Kalk and didn't have much luck with it, but many successful tanks are only dosing Kalk in their ATO water. Check the Reef Chemistry Forum stickies for info about that.

 

[smspring]

I appreciate the input... I should also add that I do auto water changes. It sounds like I would have more success with adding the supplements to the new saltwater bucket/source, since that is consistently replaced, rather than an inconsistent fresh water topoff... Would that work?

 

[Sk8r]

What you do---dose individual stuff into the sump to 'set' your numbers where I have mine in my sig line---then stop dosing and put 2 tsp kalk powder per gallon into your topoff water. That will supply the calcium for your corals, and alk and cal will hold rock steady where you set them until the mag level falls below 1200. It's magic---the sort the ocean does by dissolving old corals and coral sand with an alkalinity of a certain level. Cheap kalk powder? Mrs Wages Pickling Lime is what I use.

 

[thegrun]

Beyond the issue with variable evaporation amounts changing how much you dose, if you combine the alkalinity, calcium and magnesium together it is going to precipitate out of the water column.

 

[disc1]

Beyond the issue with variable evaporation amounts changing how much you dose, if you combine the alkalinity, calcium and magnesium together it is going to precipitate out of the water column.

THIS +1. You can't mix the calcium or magnesium with the alkalinity because it will precipitate calcium or magnesium carbonate. You can't mix the magnesium with the calcium or it will precipitate calcium sulfate.