A lot of it has to do with personal preference. They all can do what you want. It is just a matter of picking the ones that will do those functions for you. Also you may want to add things once you get into it so that may be something to think about when deciding. I have used the RKE and Archon from Digital Aquatics and several of the Hydros controllers. I have no experience with any of the others. If you want PH, temp and ATO your best bet with Hydros is on of the X4 starter kits. The X3 has a pH port but does not have a drive port for ATO. You can get the X3 Pro Pack when it becomes available with the XP8 included and use it for ATO pump drive. The X4 would leave you with more expansion without having to get another control unit to add since it has 2 probe ports (pH and/or ORP) 4 sense ports ( one is used for temp) the other three can be another temp, leak detectors, TDS meter, water level sensor ( you will need at least one for ATO, it comes in the ATO kit if you get the kit) and various other sensors. 4 0-10v inputs (breakout box and button box available third party for these). 4 0-10v outputs that can control pumps and lighting that can be controlled by a 0-10v control signal. and two drive ports which can control 12v pumps and solenoids among other 12v devices. I have float switches hooked to the sense ports on mine. They were already in place from the controller I was replacing with the Hydros. If you are in to DIY there is a good DIY section on the Hydros forum here https://forum.coralvuehydros.com/forums/diy-hydros.28/ .
I don't know that I would agree as I have been able to do everything that I was doing with my Archon with the Hydros. That includes controlling the RODI. It automatically refills the DI storage for ATO when It goes low. It also automatically transfers water from my mix tank to the fesh saltwater tank when the fresh saltwater tank goes low as long as the mix tank is ready for use. Once the transfer completes it automatically refills the mix tank with DI water. All I have to do is add the salt mix to the mix tank and press a button when it is ready for use. It dies this along with all the task at the tank. Is there something you want the Hydros to do that it does not do?
Thanks for the good insight! I am leaning toward the Hydros for a number of reason and one being I dont care for any programming and for years (i dont want to say any names), but Neptune apex seems to thinks too highly off themselves. Maybe I am wrong in my thinking but that is what they give off to me. I can honestly say I was hoping that ecotech would make a controller some day as that would be outstanding but given I trust their interface for pumps, lighting, and dosing I wouldnt want a apex which controlls everything like dosing, waterchanges(absurd), etc.
As far as heater control you can power a pump if that provides heat to the tank instead of a heater. I would have redundancy with it regardless. You can have a controller like the Inkbird as the main controller and have the Hydros turn off the outlet if the temp gets too high. I have the smaller type heaters that have their own thermostat so I use their thermostat as a backup and use the Hydros to control them. I use the Hydros to control the ATO. I have used it a little over a year. I am currently using a Hydros dosing pump as the ATO pump off a drive port. Its flow rate is 43ml a minute so it does not pump very fast. The ATO recipe on the Hydros has a few built in safety measures you can use in the advanced settings. The first two screenshots are of the ATO output settings. It all would not fit on one screen of my iPad so I took two screenshots. You set the type of output. In this case it is set to ATO. The level input on the ATO is the water level sensor used to determine full on for the ATO. The output device is the port where the pump is attached. I have it set if the input is unavailable it will turn off the ATO. Power save range is something in the new firmware. This has not been released yet but when the output is on and the power is out of range it will send an alert letting you know there is an issue. The power notification level is the alert level The are four levels none, yellow, orange and red. The type of alerts these have are setup in the options settings on the app. The ATO active in modes is wether it is able to run in the different modes such as feed, water change, low power. A few come setup but you can add your own modes also. The depends on setting is if you want the output to depend on another outputs state. Here I have it set to the ouput named ATO OK which I created. The dependency mode is off if off. If ATO OK is off the ATO will not run. I have advanced settings enabled on this output. Here I have minimum off time set for 30 minutes. So it has to be off at least 30 minutes between top offs. The next one is maximum off time. I have it set for 6 hours. If for some reason it stays off more than 6 hours it will send an alert for that. It would not be normal for it to go that long without topping off for my tank. I have minimum on time set for 2 minutes and 30 seconds. it will run at least that long regardless of the water level sensor. I have the maximum on time set for 4 minutes. I have run past maximum on time set to off. So the longest it will run is 4 minutes. If it goes to 4 minutes the pump will stop and an alert will be sent. The notification level is the level for the maximum off and maximum on time. If it does run past maximum on time the ATO stops until you intervene. So in my case the most that will be pumped at any one time is 172ml if my math is right. So that means the maximum is 172ml every 30 minutes unless it run to 4 minutes then it would stop until I reset it by manually turning off the ATO output and putting it back to auto. The last two screenshots are the ATO OK output. This is a generic type output which is set for 4 inputs. Those are two leak detectors which have to be dry for this output to be on. The third input is a DI Low which is the low sensor in the DI storage tank. That sensor has to be wet for the output to be on. The forth sensor is a water sensor that detects a high water level in the sump. That sensor has to be dry for the output to be on. The combiner mode for this output is AND. This requires all the inputs meet the requirements for the output to be on. The other one is OR with that if any one input has it requirements met the output would be on. The output has no output device assigned since I just use it for logic and not to control an actual output. This output has its depends on setting set to the return pump output. The dependency mode is off if off. So if the return pump is turned off this output would go off and so would the ATO output. Hope I didn't bore you to much, but I figure this would give you an Idea of how the ATO works on the Hydros. Since I use a dosing pump my on times are a lot more than what you would want if you were using the Hydros ATO pump.
