How much flow for a 210 ?

[koll12]

So I currently ave a 210 which I run with a Mag 18 .. Would it be better to go to a reefflo dart ? I just feel like I dont get a enough flow

 

[Toomnymods]

you do not need a large amount of flow going thru your sump.. you want to add vortech mp40's on oppisite ends to create your random flow inside the tank. if you have a lot of flow going thru the sump it cannot do what it was intended to do and that is get rid of excess nutrients by skimming, refugium needs slow flow to eat up the nitrates, and carbon to get rid of harmful toxins, before returning back to the main display

 

[koll12]

Isn't it better to be turning the water over more and more ?

 

[buckeyereefer1]

Isn't it better to be turning the water over more and more ?

not thru the sump area though. the general rule is the 3x to 5ish x's the volume of your display tank. your's is 210 so 600GPH to 1100GPH would be sufficent. i would stay closer to 750ish range myself. but also depends on the size of your sump.
the higher rate of turning the water volume you hear about is using powerheads in the display to move water around in there. such as Vortech's , Tunze, Koralia's and such. or wavebox's and also closed loop system's.