How to add and control a Carbondoser

[shaywood]

I'm adding a carbondoser to my apex 2016. Can someone walk me through how to set it up on my controller?

[Alain B]

What kind of carbon doser ? what do you intend to do with it ?

[shaywood]

I'm adding a calcium reactor to my tank and will use a carbondoser (https://tinyurl.com/kpwv568) as my regulator.
I would like to use apex to control the ph in the reactor.

[Alain B]

Those are the best , i have one running for 5 years without a hiccup . You can control the bubble rate and the bubble size by varying the regulator secondary pressure . I have Two Little Fishies Reborn for media and i also had 18 % of Remag to maintain magnesium level .

Here is my programming :

Carbon doser :

Fallback OFF
Set OFF
If CaR_pH > 6.50 Then ON
If Sys_pH < 7.50 Then OFF
If Output Calc_R_Recir = OFF Then OFF

Using this type of programming , you can had some VO to advise you if there is an effluent flow problem or the CO2 tank is nearing empty . The whole set up is based on carbon doser output timing , it has work perfectly for the last 5 years without any issues . Actually if you are ready to spend some money on a variable speed peristaltic pump : it become a set and forget operation except for alkalinity check once in a while . In the future , if Neptune can make a reliable alkalinity monitor , you could even program the Apex to set the calcium reactor by itself . Hope they are working on this !

[shaywood]

Thanks! I'll give it a try.

[shaywood]

Do you find the Doser turning on and off excessively as it stays at 6.5? Should I be worried about this?

[Alain B]

Mine is running this way for 5 years , i dont think it is an issue .

[shaywood]

Thanks again. Just curious what is your Seconds per Bubble on the Carbondoser? Also, what pressure do you have the secondary valve set at?

[Alain B]

Thanks again. Just curious what is your Seconds per Bubble on the Carbondoser? Also, what pressure do you have the secondary valve set at?

My doser is set a 4 and i use 12 psi as secondary pressure . CaR-pH.PNG

As you see on the graph , the doser work at a very steady rate , this is permitting me to detect with an alarm if the CO2 bottle is nearing empty or if i have an effluent line problem . So basically , except checking alkalinity once in a while , i absolutely never look at it .

[shaywood]

Are we able to set the high/low range for the pH range? Think it's called Hyerthesis?

[Alain B]

Yes , you can enlarge the pH range for the calcium reactor , however i dont see the purpose of it as you have an electronic doser . If a regular solenoid operated doser is in use , it will help to cool it down a bit as it is not energize as often . I prefer to operate my reactor this way as it will provide the most stable system . Remag does not dissolve very well as soon as the pH rise a bit . Also enlarging the pH range make the alarm for low CO2 and effluent flow more difficult to set .

[shaywood]

From your graph, it appears the controller keep he pH between 6.52 and 6.49. Mine varies between 6.51 and 6.46 How do I tighten the range? I set my doser at 4 spb and 12psi.

[Alain B]

If you look carefully , you will see that the pH varies from 6.49 to 6.51 with a 6.52 on occasion . It is not recommended to run a reactor at a lower pH setting ( 6.5 ) is the lowest limit ) , as it might turn the media into mush . How big is your tank , what kind of corals do you have ? how many ? All the parameters i had mention are related to my system , your most likely will be different . However the principle is the same for all . Start at a slower setting , it can be increase if needed .
Post your doser setting ?

[shaywood]

Ok Thank. I have a medium stocked SPS/LPS tank. 92 gallon Red Sea Reefer 450.

[Alain B]

If the effluent flow is stable , you will see a graph similar to mine . Your programming is ok . What kind of flow do you get from the effluent ? Do you have a measuring cup ? If so , set the cup under the effluent line and measure the flow for 5 minutes . Divide the result by 5 and post the result . Normally when the pH drop way lower then the setting , it denote too much CO2 injection , or a very slow effluent rate . it might need some fine tuning . What kind of reactor is that ? Brand and model ?

[shaywood]

I increased from 20 to 30ml/min this morning. Its a GEO612.

[Alain B]

It is a very slow rate , reduce the CO2 injection , slow the bubble rate to 8 or 9 seconds between bubble and drop the secondary pressure to 8 psi, this will reduce the bubble size , slowing the CO2 injection ; let it run for a few hours , it will stabilize . Check the graph after . Also it would be a good idea to measure the tank alkalinity and calcium level . Just to find out if the system is in balance . It is a good opportunity to balance it . The Geo 612 is very short and does not contain much media , it respond very quickly to pH change . Alkalinity level need to be maintain first with effluent flow , second with pH .

[shaywood]

I'll make the changes you recommended. The alkalinity hasn't stabilized in the tank yet, which is why I've had to adjust the effluent flow rate. So far, the Alk keeps dropping slightly. Will let you know

[Alain B]

Dont chase alkalinity number , otherwise you will chase those for weeks . Make the change to the calcium reactor and wait it out for at least a day . After a day , dont touch anything and measure the tank parameters . record those and wait another day, still dont touch anything , then measure the parameters again . You need to set the calcium reactor first , from there it all will be easy when you have a basis to make change . In the meanwhile , you will get a good graph for the reactor operation . We can work it out from there .