geo reactor

[jose hernandez]

so im setting up a red sea reefer 750xxl i am goin with a calcium reactor so i decided on a geo which model number will i need this will be a sps dominat tank

 

[RandyC]

The size of the reactor only dictates how often you'll have to change the media. It doesn't provide a more concentrated effluent. I would recommend getting the largest reactor (with a secondary reactor) that space will allow in your cabinet to reduce your maintenance schedule times.

 

[jose hernandez]

so i would need dual recators?

 

[FMF0331]

i'm using the geo 612x2 model on my 200 gallon sps dominant tank ..
i love it

 

[RandyC]

so i would need dual recators?

You don't need it, but a secondary reactor can help slightly increase pH levels of effluent before it is dripped back into the tank.

 

[vetteguy53081]

Model 612 or 618

 

[Water Dog]

At a minimum, I’d go with a 618. If you want a secondary effluent chamber, then add an SMC415.

 

[rossco]

I agree with a 618. My fully mature sps dominant 210 requires an 818.

 

[bdare]

Why would you choose the 618 over the 612x2 when both are rated for 300 gallons? I'm also trying to decide which is a better option for a 220.

 

[jose hernandez]

That was my next question wouldn’t I be better with the dual 612 x2 they both are rated for 300 gallons

 

[bdare]

That was my next question wouldn’t I be better with the dual 612 x2 they both are rated for 300 gallons

The 612x2 holds more media and more time for the pH to increase? I'm not sure, but very interested to see what the experts say. I actually sent this same question to the sales email on the Geo website...

 

[jose hernandez]

I contacted geo they recommended the 618 along with 415 so I contacted them again and asked couldn’t I use the 612x2 and they said yes

 

[bdare]

I contacted geo they recommended the 618 along with 415 so I contacted them again and asked couldn’t I use the 612x2 and they said yes

Now I'm more confused. Are they suggesting a 618 with a 415 is equivalent to a 612x2? Or just that both would work?

 

[Water Dog]

I would go with the 618. It’s the media in the main calcium reactor chamber that matters. As far as I’m concerned, the 612x2 is just a 612 with a 612 sized secondary chamber. It looks pretty and all, but the 618 with the 415 secondary chamber can handle more.

 

[rossco]

The tank size recommendations are educated guesses at best, and most likely based on a moderately stocked tank. I maxed out a CR 618 on my previous 75 gallon. It was so full of Acros that they touched the glass and I could no longer scrape it.

I would only go with a CR612x2 if your cabinet isn't tall enough for a CR618. The media in the second chamber does very little to help with alk and CA supplementation and for raising the pH. When I was going down the "chase the pH rabbit hole" I added a GEO UMC 618 as a second chamber for my CR818. The pH maybe went up by 0.1 , and in the 3 years I have had it set up, the #5 size crushed coral media has settled maybe an inch and a half which is very little consumption.
In comparison, I need to add 12 -15 pounds a year of #15 crushed coral (basically the same thing as Reborn media) to the 818.

As I was typing this @Water Dog replied the same info.

By the way, a Kalk reactor in line with an ATO brings the pH back up nicely.

The 75 gallon:

 

[jose hernandez]

YOU SAY HANDLE MORE WHAT DO YOU MEAN IF BOTH UNITS ARE RATED FOR THE SAME AMOUNT OF GALLONS SORRY FOR ASKING SO MANY QUESTIONS WHEN I CONTACTED GEO I ADDRESSED THIS CONCERN BETWEEN THE TWO THEY SAID EITHER ONE WAS GOOD SO IM CONFUSED NOW 612X2 OR 618 WITH THE 415 THIS WILL BE MY FIRST TIME USING A CALCIUM REACTOR SO WANT TO GET IT RIGHT DONT WANNA WASTE MONEY BUYING A UNDERSIZED ONE

 

[vangvace]

Go with the 618 with the 415 second chamber, that way if need be you can upgrade the secondary chamber to a larger unit vice having a pair of 612s without a volume increase path. The 618 is also a smaller footprint than the dual 612s and even a reefer 750 runs out of space quicker than you think.

 

[Water Dog]

Again, a 618 is bigger than a 612. When looking at reactor size / capacity, only look at the main chamber which has the recirculation loop, pay no attention to the secondary chamber as it has no bearing on capacity, it only serves as a CO2 degassing chamber. Again, with the 612x2, you’re essentially just getting a standard 612 with a 612 sized degassing secondary chamber that just happens to be attached. So as reiterated multiple times, if you want more capacity and less frequent maintenance / refilling of the media, go with the 618.

Another thing to consider is when it comes time to clean the CaRx out and add new media, you’ll be very happy that you have two distinct, separate chambers for ease of maintenance.

 

[Bpb]

I’ve gotta disagree with those recommending a 612 or even a 618 for a tank that size. I run a 618 on my 90 gallon sps tank, and have to refill it probably every 6-8 months. A 750xxl when fully stocked will need at least an 818 as well as full saturation kalkwasser to keep up and you’ll still be replacing media annually or more

 

[jose hernandez]

not worrying about maintenance don’t mind it at all just wanna get a reactor that will be More than sufficient if not double my water volume this will be a sps dominant tank so don’t wanna be dosing or adding kalkwasser want the reactor to do that 4 me