ACIII PH safeguard needed

[SteveM]

I have my ACIII programed as follows to turn my CO2 on and off for my calcium reactor.

If pH2 > 06.46 Then CO2 ON

If pH2 < 06.41 Then CO2 OFF

 

Tonight while I was at work I just happened to check my ACIII from the internet and noticed that my tank PH had dropped to 7.66. Apparently this happened from the CO2 not shutting off. Luckily it kicked off and the PH slowly came back up to a normal range and nothing was affected by it.

 

Is there anyway to create a safeguard for a CO2 solenoid that sticks and does not shut off when the command for the CO2 OFF is given?

[MisterTang]

How does the solenoid connect to the ACIII? Is the solenoid wired to a wall wart/box or something, and you have it plugged into one of the 120V outlets?

[flowerseller]

Steve,

 

What was the pH of the reactor at the time the tank pH was 7.66?

I ask because you may need to re charge the reactor or increase evaporation to use more kalk.

Look at the graph readings because it's likely the tank pH was near that before.

 

If pH > ??.?? Then CO2 ON

If pH < ??.?? Then CO2 OFF

 

??.?? will be the range you like to keep.

 

Also, an alarm code to text you a message is in order.

 

If pH > 08.60 Then ALM ON

If pH < 07.50 Then ALM ON

 

I keep mine open ended so it keeps texting me until the problem is corrected.

 

BTW,

What media are you using? That seems like a pretty low reactor pH, especially if you use a small grade media.

[ctenophore]

I have my ACIII programed as follows to turn my CO2 on and off for my calcium reactor.

If pH2 > 06.46 Then CO2 ON

If pH2 < 06.41 Then CO2 OFF

 

Tonight while I was at work I just happened to check my ACIII from the internet and noticed that my tank PH had dropped to 7.66. Apparently this happened from the CO2 not shutting off. Luckily it kicked off and the PH slowly came back up to a normal range and nothing was affected by it.

 

Is there anyway to create a safeguard for a CO2 solenoid that sticks and does not shut off when the command for the CO2 OFF is given?

Do you know for sure that the CO2 did not shut off? If the solenoid is failing then there's not much you can do via AC3 except send alerts like Chip mentioned. You need a new solenoid that is reliable. I suppose you could plug the reactor feed pump into the DC8, and turn that off if tank pH falls too low in event of solenoid failure.

 

If the solenoid is not failing, then you could add another condition based on tank pH to the CO2 on/off:

 

If pH2 > 06.46 Then CO2 ON

If pH2 < 06.41 Then CO2 OFF

If pH < 07.70 Then CO2 OFF

[SteveM]

I use the GenX C.R.M. large media and I found that if I go much higher with my PH settings it will not dissolve the media.

 

The PH in the reactor had dropped to 6.30 when the tank PH dropped to 7.66. Once the solenoid kicked the CO2 off the tank PH began to slowly rise. My normal range on my graph for PH is between 6.40-6.48 so if definitely stayed on to long.

 

I do have that exact alarm code set but luckily for me it didn't get low enough to kick it on.

[jason the filter freak]

There is a real simple way, albeit expensive-ish. Install another solenoid in line with the first. Redundancy = safety

[MisterTang]

There is a real simple way, albeit expensive-ish. Install another solenoid in line with the first. Redundancy = safety

 

Yeah, that's what I was going for. Also, if it's just stuck, I would write a block of code that would turn it on and off again a couple of times to see if I could jimmy it into proper position, if the pH fell to an even lower level.

[jamesbuf]

plug the reactor feed pump into the DC8, and turn that off if tank pH falls too low in event of solenoid failure.

 

 

 

That is what I was going to suggest.

[SteveM]

Do you know for sure that the CO2 did not shut off? If the solenoid is failing then there's not much you can do via AC3 except send alerts like Chip mentioned. You need a new solenoid that is reliable. I suppose you could plug the reactor feed pump into the DC8, and turn that off if tank pH falls too low in event of solenoid failure.

 

If the solenoid is not failing, then you could add another condition based on tank pH to the CO2 on/off:

 

If pH2 > 06.46 Then CO2 ON

If pH2 < 06.41 Then CO2 OFF

If pH < 07.70 Then CO2 OFF

 

 

Great ideas, thanks. I think I may do both. Add the second setting based on the tanks PH and also plug the feed pump into the DC8.

[Rascal]

Steve:

 

There is an easy fix for this. I had this same problem at first. I did some research and found out that sometimes the solenoid uses such little power that the DC8 won't switch it on and off like it is supposed to. Here's the explanation from some guy named Jansenwrasse on RC:

Be careful using your CO2 solenoid on the DC's The solenoids use very little energy to open and close the switch and sometimes if the Neptune tries to turn off the outlet there is not enough voltage drop in the line to close the relay. The solution is to put in a cube tap (1 outlet makes 3 outlets), or a powerstrip and put a fan or something that will use a little more power so that the relay will close.

 

Following this suggestion I plugged both my solenoid and the recirc pump for my reactor into the same outlet on the DC8, and that solved the problem.

 

Mike

[flowerseller]

Steve:

 

There is an easy fix for this. I had this same problem at first. I did some research and found out that sometimes the solenoid uses such little power that the DC8 won't switch it on and off like it is supposed to. Here's the explanation from some guy named Jansenwrasse on RC:

 

Following this suggestion I plugged both my solenoid and the recirc pump for my reactor into the same outlet on the DC8, and that solved the problem.

 

Mike

I would think you will want to rethink that.

 

On another note;

I do not like the idea to shut the feed flow off to a CA reactor.

With no new flow, they foul very quickly.

[SteveM]

 

On another note;

I do not like the idea to shut the feed flow off to a CA reactor.

With no new flow, they foul very quickly.

 

Chip, don't you think that just as a safety feature it would be okay to do this to keep the ph from getting to low? Should it happen I could always control the flow off and on via the ACIII until I could get home to fix the problem.

[Rascal]

I would think you will want to rethink that.

 

On another note;

I do not like the idea to shut the feed flow off to a CA reactor.

With no new flow, they foul very quickly.

 

Chip:

 

I agree with you about not shutting off the feed flow (it would go anaerobic, right?), but the way I have it set up the feed pump doesn't turn off at all, only the recirc pump and the solenoid. You could also accomplish the same thing with a small AC fan or powerhead, but this way seemed more efficient to me.

 

On the other hand, this advice from Neptune's guy on RC:

 

"If it is only an issue with the AC adapter not drawing enough current then you shouldn't need a new solenoid. Move the device to DC8 port 4 or port 8, these ports are relay controlled and not affected by low draw devices."

 

After reading a bit more, the first post I quoted was incorrect. It turns out that on newer (not sure what this means) DC8s ports 4 & 8 are relay controlled, the rest are triac controlled (no idea what that means).

 

It could be something else entirely, but an easy way to find out is just to try to turn the solenoid on and off manually through the ACIII. If it won't turn off, then you know this is your problem. Switch it to port 4 or 8 and/or add an additional load besides the solenoid and you should be all set.

Edited October 17, 2008 by Rascal

[flowerseller]

Chip:

 

I agree with you about not shutting off the feed flow (it would go anaerobic, right?), but the way I have it set up the feed pump doesn't turn off at all, only the recirc pump and the solenoid.

That's been my experience with others I've talked to/worked with about problems or impeaded flow thru.

 

I find your approach less threatening since it's not the feed pump but still not reciring thru itself is not pleasing to me. the water in the media is stagnant with only the surface water exchanging.

May not be an issue, may be.

I also have to realize most would have this set for a very short term fix, unless it's the day after you leave for a week vacation. my luck...............

 

 

Steve,

What I don't get is if the solenoid finally shut off at 6.30, that just doesn't seem to me to be that much less than 6.40 and be the cause of your tank pH dropping to 7.66 with 6.30 effluent versus 6.40 effluent.

Did your evap rate drop off sharply or need a kalk reactor recharge also?

[SteveM]

Steve,

What I don't get is if the solenoid finally shut off at 6.30, that just doesn't seem to me to be that much less than 6.40 and be the cause of your tank pH dropping to 7.66 with 6.30 effluent versus 6.40 effluent.

Did your evap rate drop off sharply or need a kalk reactor recharge also?

 

Chip, that was the only thing that was different. No evap change or kalk change. Even though it kicked back on while it was at 6.3 I think that the amount of time it took to go from 6.40 to 6.30 and then finally kick back on was just enough time to let the tank ph drop a little. It can get as low as 7.85 at night so it would not have taken much to get it to drop lower. It is the only explanation I have for the ph dropping like it did.