Kalkwasser or two part

[Stormy78]

Just like the title says.  I have a 20 gal fusion that will have sps and lps.  I'd like not to do weekly water changes.  Should I dose two part or top off with kalkwasser.  I have an ato and I'd get a monitor to watch it.  Weather an apex or pinpoint. 

[Five.five-six]

I use kalkwasser for topoff and 2 part for weekly adjustments when I test.  Don't forget magnesium.  

Use the apex to shutoff the ATO when the pH climbs.  

[seabass]

16 hours ago, Stormy78 said:

I'd like not to do weekly water changes.

With either, you should still do weekly water changes.  Exporting wastes and organics is as important, or even more important, as replenishing consumed elements.  Water changes are actually a fairly poor method of replenishment.  However, they are usually adequate for new systems with little coral or coralline, FOWLR systems, and soft coral systems with little coralline.

 

That said, if your consumption is small, Kalkwasser should work fine.  However, if consumption is greater, two part solution is your better option.  It's also possible to do both, like 5.5-6 is doing.  Kalkwasser adds the benefits of raising pH and decreasing phosphate.

[Five.five-six]

Use the BRS calculators for 2 part adjustments.  They are surprisingly precise and easy to use.   

 

https://www.bulkreefsupply.com/reef-calculator/