When is the best time to start 2-part dosing?

[OrthoVet05]

Hey guys. I haven’t been able to find the answer to this but have heard differing opinions from friends. When is the best time to start Randy’s 2 part dosing? Is it when you set your tank up during cycling? After? Before you add any fish? My plan is mostly to have softies and some LPS but I definitely want to be set up for SPS. Thanks.

 

[G8trBait16]

Hey guys. I haven’t been able to find the answer to this but have heard differing opinions from friends. When is the best time to start Randy’s 2 part dosing? Is it when you set your tank up during cycling? After? Before you add any fish? My plan is mostly to have softies and some LPS but I definitely want to be set up for SPS. Thanks.

I started 2 part dosing when weekly water changes wasnt sufficient at keeping my alk stable.

 

[andrewkw]

The best time is when you need to. If nothing is consuming alk and ca you are just going to keep raising the levels. Every systems demands are different but it's very possible you won't have to start dosing until you have lots of corals growing if it's going to be mainly softies and lps and you do frequent water changes (with a salt that has higher ca / alk then you keep your tank).

I know this isn't a concrete answer but the easiest way to know is to keep testing and when levels are dropping noticeably in a 24hr span then use a calculator to figure out how much you need to dose. If your tank is brand new I wouldn't bother testing daily just yet, do a few tests to get a baseline and go from there,

 

[Randy Holmes-Farley Verified Community Expert]

I agree, as soon as the alkalinity begins to drop below your target level, that's the time to begin dosing.

 

[OrthoVet05]

I started 2 part dosing when weekly water changes wasnt sufficient at keeping my alk stable.

The best time is when you need to. If nothing is consuming alk and ca you are just going to keep raising the levels. Every systems demands are different but it's very possible you won't have to start dosing until you have lots of corals growing if it's going to be mainly softies and lps and you do frequent water changes (with a salt that has higher ca / alk then you keep your tank).

I know this isn't a concrete answer but the easiest way to know is to keep testing and when levels are dropping noticeably in a 24hr span then use a calculator to figure out how much you need to dose. If your tank is brand new I wouldn't bother testing daily just yet, do a few tests to get a baseline and go from there,

Sounds good. It sounds like most people will focus on the Ca concentration in the tank, where the alkalinity is the true indication and rate limit of coral growth. The calcium is definitely necessary, but sounds like water hardness is harder to keep in balance. If you have proper hardness, then will the calcium sort itself out? Thanks.

 

[Randy Holmes-Farley Verified Community Expert]

Sounds good. It sounds like most people will focus on the Ca concentration in the tank, where the alkalinity is the true indication and rate limit of coral growth. The calcium is definitely necessary, but sounds like water hardness is harder to keep in balance. If you have proper hardness, then will the calcium sort itself out? Thanks.

On a percentage basis, alkalinity depletes way faster because there is so much less alk than calcium in seawater. Alk should always be the guide.

 

[OrthoVet05]

On a percentage basis, alkalinity depletes way faster because there is so much less alk than calcium in seawater. Alk should always be the guide.

Thanks Randy! It feels crazy to be chatting with the Reef Doctor. Did you happen to see my pool calcium chloride post in your forum? It’s rated at 75-94% calcium chloride and it’s definitely in pellet form. I took your advice and used 20% less of it to make the solution.