Spending some time this past week setting up my tank again. Having been almost 4 years since I set it up originally I had to look at some things I had done before and ask why. One of those things was, "why did I write a program in my controller to turn one of my heaters off if the temp dropped below 72 degrees?" Since I really did have a reason I wanted to share it and start a thread for people to share tips on how they use their controller to run their tank and add safety and redundancy. I have two heaters in my tank. The idea is if you divide the wattage needed between two smaller heaters you are much less likely to "cook" your tank if one of them fails in the on position. One of my heaters is in the sump. The other is hidden in my overflow. This is the one that has the program to turn the power off if the temp gets below 72 degrees. Sounds backwards doesn't it? The idea is that a temp below 72 likely means that the temp probe (which is also in the overflow) is exposed to air and ambient room temerature. In that situation, without the controller turning it off the exposed heater would over heat and likely cause a fire. Or worse, if the tank were acrylic melt a hole in the tank. What are some ways you use your controller to create simplified maintanence, safety or redundancy?
I have my salinity set that if it drops below a threshold the ATO won't function is one of my favorites. I have a stenner pump doing AWC and a float in that bin - it will not run AWC if the float detects the new water tank is low (which would drain water from the DT and if ATO is active fill it back up. Not shooting arrows at your logic there, but in my particular set up if my temp probe is exposed to air I have much larger issue at hand than a heater...I'll be calling a pump truck to vacuum my basement. Now, that I think about it...if my temp probe konks out and gives an erroneous reading is another thing...which readings at 72 or 92 so might avert disaster.......thinking......
Yeah that's pretty specific for my set up. But if your heater was in your overflow you wouldnt. The heater would likely explode or start a fire. Most people don't have a heater and probe in the overflow. Just an example of what's possible if you get inventive with controllers.
Indeed! I know I could do more with mine but I just haven't made myself do it. The profilux has a good bit of error logic and basic functions that don't require programming. And I haven't yet wrapped my head around the logic gates totally to do some more advanced stuff. I've barely scratched the surface. One thing I'd like to do: have a solenoid that's ph controlled that will open the line to a co2 scrubber if ph gets too low. Shut it when it gets back up. It had built in logic for ph controlled devices (Ca reactor, etc) but since I don't have one I haven't really spent time with it. I have some logic that prevents other processes of there is a general error as a catch all. This box has defined set points for stuff so I don't define logic for each error. I can make some more, though. There's enough built in fail safes that I haven't thought about many other failure scenarios. Maybe I should. The one thing that I'd like to do that I haven't gone through the trouble to figure out: it has more than one feed pause routine. I'd like for the power heads to run at minimum for one but turn off for another routine. Haven't dug into that. Ooo oooo! The other is that I have an awc vat that takes almost all day to fill. When that is filling it doesn't allow the ato to work and it times out because it's not filling fast enough. So I have a solenoid that works opposite of the ato that shuts down the awc vat line when ato has demand. That look 5 seconds to program.
Now that I'm thinking: another thing is that I'm comfortable with the error handling and such that I have the ato running straight off the rodi filter. No refilling ato vats, so there's that. I guess I could have logic that shuts down the doser if say, there's a huge ph spike. But what are the chances the doser would stick ON? I need another float in the sump to warn of overfilling as yet another failsafe though. However, optic floats fail off so the likely scenario is water being too low. Then if you have a permanently submerged float to warn of low water IT is likely to fail as well. So either way the more complicated you make something you can actually make it more likely to fail. I may have to learn more hard lessons with this thing though. What I haven't figured out yet that I'd like to: have an event driven logic gate run a PROCESS. I'm sure with the timers I can do it, just not sure how. When I get serious about automatic feeding then I'll be all fancy. Turn off main pump, skimmer, quiesce power heads, run doser to pump food into the tank, reverse to clear lines, wait 15 min, fire up pump, wait 30 more minutes for skimmer. Something like that. I know it can do it, just haven't invested the time yet.
