Looking for Input on Timers for My Reef Tank

Hello everyone!!! I’m diving head first into the deep end here. I purchased two Kasa HS100 Smart Plugs specifically because they work with Smartthings. It’s my intention to use them to control the water flow within my reef tank. I have two powerheads. Powerheads basically blow water around the tank. There’s a powerhead on the right side of the tank, and one on the left side of the tank. Starting at 9 in the morning and ending at 9 in the evening I want each pump to run 3 minutes on, 3 minutes off, with a 1 minute interval where both pumps are running. I’m guessing this can be accomplished by staggering the start times by 1 minutes. This will create the varied turbulent flow essential to the health of a reef system. I will spend time tomorrow morning reading the various articles for newbies, like myself. I hope someone out there has done something similar to what I’m trying to do, and I hope this post serves as a path to open a dialog. It would be really great to have like minded people I can bounce ideas off. Wish me luck!!! I thank everyone in advance for your help.

SmartThings is just not reliable enough to trust a reef tank to if it’s for anything other than ornamental purposes. That’s not just me that says that, the company says so in their product usage guidelines:

Data accuracy and consistency from SmartThings sensors, including those provided by SmartThings directly, resold by SmartThings, or supported by SmartThings, is not guaranteed. Therefore, you should not rely on that data for any use that impacts health, safety, security, property or financial interests. For example, because temperature readings may vary significantly from reading to reading on an individual device, between devices, or over time, those readings should not be used to control heating and cooling in environments where food spoilage, health risks, or damage to physical goods could occur.

  • SmartThings allows for the control of electronic devices through pluggable outlets and supported third party switches, outlets, relays and controls. Where possible, SmartThings has worked to ensure message delivery and control reliability, but many factors can impact this, including electromagnetic interference, solar flares, wireless and cellular connectivity, and the natural complexity of software instructions that might be in direct conflict caused by SmartApps or by end users. These and other issues can cause commands to not be delivered, to be delivered repeatedly, or to be delivered in rapid succession. Therefore, do not use SmartThings to control any device that may have an impact on health, safety, security, property, or financial interests, or where the device is sensitive and could be damaged by power cycling or power surges. For example, do not control medical equipment or expensive electronics with SmartThings.

For the type of application you’re talking about, you’re better off just getting a regular dumb timer outlet. It will be much more reliable.


It’s interesting you say that. I am, at the moment, using dumb timer outlets. They are made for use with hydroponics. No big loss. I plug those timers into the wifi outlets. At least I can tell Alexa to turn the pumps off for 10 minutes so I can feed the fish. Thanks for the input.

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For me, it all falls to the FMEA (failure mode and effects analysis). If the ST systems fail to fire, what is the effect? Is it death to the things in the tank, or is it less pretty? How long do they need to be inactive for it to go bad? What will happen if the internet goes down?

If the ecosystem can handle the system being down, or you have a back-up and a warning system if it goes down, then you can use smartthings.