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Allmost
03/31/2011, 08:04 PM
Hello

Can someone help me understand tank size recommendation for CR ?

I often hear ppl say their CR can't keep up, can't they increase the flow? Or replace media more often ?

I want to buy a vertex rx4 CR and it is rated for 180 gallons and my tank is 160 gallons. Full of sps. Would it be able to keep up? Or should I give with a larger version.

Thanks.

tkeracer619
03/31/2011, 09:33 PM
Get the larger version. AFAIK you cant go too big but you can go too small. I pretty much have my reactor maxed out. Its struggling to keep up but so far so good. I will probably be going to a bigger reactor soon.

Allmost
03/31/2011, 09:55 PM
Are you running it 24/7 ?

das75
04/01/2011, 12:10 AM
with a doser really no limitations, if your demands increase you just increase your flow, compared to wondering if you're going to max out your reactor

Wrench
04/01/2011, 07:08 AM
IMO a calcium reactor will replace elements other than calcium which minimizes the need for supplemental dosing. I believe that all of the elements the corals need can be found in the reactor media which are returned to the system by the reactor. Not a big deal if you're doing regular water changes I suppose. I'm partial to reactors because I'm lazy.

Allmost
04/01/2011, 09:17 AM
with a doser really no limitations, if your demands increase you just increase your flow, compared to wondering if you're going to max out your reactor

can you explain what it is you mean ?

what does it mean to max out a reactor ?


so was my original statement correct ? ppl who say their CR can not keep up, should just run it for longer hours and higher flow ?

do you know this from experience ?

Allmost
04/01/2011, 09:18 AM
IMO a calcium reactor will replace elements other than calcium which minimizes the need for supplemental dosing. I believe that all of the elements the corals need can be found in the reactor media which are returned to the system by the reactor. Not a big deal if you're doing regular water changes I suppose. I'm partial to reactors because I'm lazy.

thanks for the info, but I was asking how can a reactor not supply enough CA++ for a reef system ....

I am talking about SPS reef which consumes 250 ML of carbonate daily !

das75
04/01/2011, 02:19 PM
Have a DIY reactor and have adjusted by increasing effluent flow and bubble count to meet changing demands, though did find when pushing needed a lot of attention to prevent alk spiking. Just there's got to be a point where increasing the flow you'll be reducing contact time for a reaction and also having CO2 not being absorbed and building up.

My comment with a dosing pump system is say you're adding 60ml/day of a 2 part solution to maintain a low demand tank, your system takes off, lots of SPS growth, you just spin the pumps longer. The pump I'm looking at flows 2.5ml/min so for my system rather than running 1 min every hour, I set it to run 2 or 3 minutes every hour.

Other thing is look at it from a price point, dosing systems are relativity cheap compared to a high end reactor and CO2 rig (and solenoids and controllers if you choose to use then). Supposedly there's a roll off in savings when using dosing solutions compared to reactor media but with DIY recipes it's when the display/system volumes are hundreds of gallons (there's a thread around with tables and graphs I can't find).

I will though agree with Wrench's point, reactor media does add trace elements but as he also said, so does water changes.

tcmfish
04/01/2011, 02:30 PM
Don't post in this forum much, but...

It is my understanding in a small CR if you increase flow, you decrease the time the water is spending in the reactor, obviously. That means the CO2 has less time to dissolve and the pH in the reactor will be higher (less calcium being put into the water) and the water going back to the tank (effluent) will have more CO2 in it, in turn making your tank more acidic. Even though the pH will be higher in the reactor that is just because it is constantly being replaced tank water, but the extra CO2 will make the overall pH lower because it is not reacting with the media.

You can't really just ramp everything up. If you ramp up flow, then you have to ramp up bubble count and eventually you will reach a point where the CO2 won't have enough time to react with the media or dissolve.

Go Bigger.

Allmost
04/01/2011, 02:41 PM
Have a DIY reactor and have adjusted by increasing effluent flow and bubble count to meet changing demands, though did find when pushing needed a lot of attention to prevent alk spiking. Just there's got to be a point where increasing the flow you'll be reducing contact time for a reaction and also having CO2 not being absorbed and building up.

My comment with a dosing pump system is say you're adding 60ml/day of a 2 part solution to maintain a low demand tank, your system takes off, lots of SPS growth, you just spin the pumps longer. The pump I'm looking at flows 2.5ml/min so for my system rather than running 1 min every hour, I set it to run 2 or 3 minutes every hour.

Other thing is look at it from a price point, dosing systems are relativity cheap compared to a high end reactor and CO2 rig (and solenoids and controllers if you choose to use then). Supposedly there's a roll off in savings when using dosing solutions compared to reactor media but with DIY recipes it's when the display/system volumes are hundreds of gallons (there's a thread around with tables and graphs I can't find).

I will though agree with Wrench's point, reactor media does add trace elements but as he also said, so does water changes.

I have been balling for last 6 years, DIY two part before that.

now I want to go with CR.

thanks for the info though.

Allmost
04/01/2011, 02:44 PM
Don't post in this forum much, but...

It is my understanding in a small CR if you increase flow, you decrease the time the water is spending in the reactor, obviously. That means the CO2 has less time to dissolve and the pH in the reactor will be higher (less calcium being put into the water) and the water going back to the tank (effluent) will have more CO2 in it, in turn making your tank more acidic. Even though the pH will be higher in the reactor that is just because it is constantly being replaced tank water, but the extra CO2 will make the overall pH lower because it is not reacting with the media.

You can't really just ramp everything up. If you ramp up flow, then you have to ramp up bubble count and eventually you will reach a point where the CO2 won't have enough time to react with the media or dissolve.

Go Bigger.


thank you for the great Explanation. Boomer was able to explain to me this as well :) makes sense, and now I know why I want a bigger Calcium reactor. and can adjust the cost difference and space difference (only 150 more but 4" more under cabinet :S)