2part v. reactor cost analysis

I was looking at hooking up a calcium reactor to my system so I did some research since everyone says how much money I would save on my 210g system with 150ml a day useage on each.

I have only ever bought 5gal buckets during a group buy. And I always end up needing carbon and gfo then so I never paid shipping before... (all numbers are group buy prices if available and all came from bulkreefsupply.com)

So, for a 5gal which is a total of 80 cups of media in each bucket.
$66.39 for cal during group buy
$66.39 for alk during group buy. - So... $132.78 per purchase. And this is a cost of $0.83 a cup

It takes 2.5 cups to make a gallon of Calcium and 2 cups/gallon of Alk...

So.. in 1 year I am using 14 gallons. Or 35 cups of the Calcium and 28 cups of Alk or a total of only $52.28 a year for both...
I also replace the tubes in my doser annually at $10 each so =$20 total

Reactor:

CaribSea ARM Reactor Media - Extra Coarse, 1 Gal - English - (I guess that's good) $20, assuming you get free shipping
And a new ph probe every 12 months at minimum - the brs brand is only $24 during a group buy
Refill the 10lb Co2 = $15 after a phone call to my local welding shop

So, a total of $59 for CaRx media and monitoring annually
And a total of $72.28 a year for my do my dosing system A difference of $13.28/year

2 pumps cost $140 total..
Reactor and all is conservatively $500

It will take 27 years at the $13.28 a year difference to recover the difference on savings.. If my consumption DOUBLED (impossible, i'm full of sps literally) I would need still need 5.5 years to recoup the savings...

 

wow thanks grim this helps alot. now I will probably be dosing instead of a reactor in the new setup.

 

I have a 225g sps tank. There is no way in hell I would ever, ever go back to dosing. Way to much work. You have to consider maintenance time, testing time, and test kits. If you are not on top of those things, you are bound to have problems. I've got a huge calcium reactor and a 20 pound CO2 tank. I expect no more than yearly maintenance just like in years past.

 

I fully disagree with the workload... I make a 1 second adjustment to my apex which takes literally 1 minute tops... I mix up new containers every 6 months... Weigh it, shake it put the line in, and I know I'm good. And I don't have to redial mine in everytime I put in new media like a reactor.

Past that, no matter the method most responsible reef keepers will test monthly either way. Neither system will ever allow you to walk away from testing. And if consumption increases on a reactor you still have to adjust either the effluent rate or drip rate. Which is no easier than adjusting a couple seconds on my doser.

 

I guess it pays that I have a AquaC reactor that holds 5 jars of media. I've had it for 5 years so setting it and tweeking it is nothing. Then again, I tune with a ph probe so dialing in the right bubble rate to the effluent rate is a snap. I could see how it would be hard without that method.

I am just telling you based on my experience. At the time, my SPS load was very high (many sps being 20"+ accross), and it became tedious to fill the reservoirs. My definition being every 10-14 days. I guess I should keep in mind that I live in Southern Cali where we don't have time for anything so what seems like more work to me may not feel that way for others.

Either way, I have chosen to go back to my trusty calcium reactor. And I might add that I am sorry for cheating on her!

 

I was dosing two part until a few months ago. I didn't have an apex dosing pump so I had to manually dose alk and cal, day and night. I recently got a great deal on a used calcium reactor and love it. I think if you are coming over from manually dosing the reactor is great, but if you already have a dosing pump system in place you probably wouldn't want to switch anyway.

 

Nice price breakdown.

There is a sticky that covers the debate well:
http://www.3reef.com/forums/water-chemistry/2-part-dosing-vs-reactors-74496.html

 

Great thread. I have both kalk reactors and calcium reactors but I feel like I figured out my 2 part dosing pretty well so Ive been sticking to that method. Thanks for doing all the math grim!

 

I took it the next step. Because 2 part isn't 2 part.. it's 3 part... and, with a reactor, dolomite addition is CHEAP! But... so is Mag dosing

So...
Did some math on the Mag dosing

You need a 5 gal of each for max savings from BRS or 80 cups of each
Magnesium Cloride - 80 cups / $66.39 = .83/cup
Magnesium Sulfate - 80 cups / $67.99 = .85/cup

To make a gallon = 5 cups of sulfate and 3 cups of chloride or $6.74/gallon
BRS says you should use 20 oz to every 1 gallon of alk/cal or 15.625% of the consumption of those two

So in a year on my system.. at 14 gallons of two part consumption I'm using 2.187 gallons of mag a year. Which is only $14.74 a year.. even double is only $30 for mag


So... Even with DOUBLE my current consumption it will take 4+ years to recoup.

 

Let’s assume for a moment that my 2 part demand was doubled as my reef grows in, putting your annual cost at about $125 for the 2 part and doser tubes without taking Mg into consideration. Now say that Mg dosing costs the additional $30 annually, yielding a grand total of $155 annually. Equipment will have a $140 startup cost. (+ controller or timers, Most have these though)
Year 1: $295
Year 2: $450
Year 3: $605
Year 4: $760

The Calcium reactor media, cost about $18 for a year’s supply, plus the $15 for a CO2 refill annually and another $30 on a ph probe. The dolomite costs $13 for a 2 year supply, putting my annual cost at about $55 plus the $500 for the reactor setup. (If you have a controller...)
Year 1: $610
Year 2: $665
Year 3: $720
Year 4: $775


I have never kept any piece of aquarium equipment for over 4 years personally...