chiller on-off points

[robert teseo]

so, set it too tight and it cycles a lot, too wide a spread means temps are up/down all day. currently I have 1 deg f. what is a good number to set? oh yea, mine also has a heater built in to complicate the issue

 

[Ocelaris]

Good question, I'm going to tag along as I'm getting a chiller tomorrow. I hit between 75 and 78 during the day, and that seems fine, but I may lower the cycle to 2 degrees, no higher than 78 when I get the chiller hooked up. But I'm curious what others think. With some of my big lps like acanthophyllia, I've heard no higher than 78 is key to their long term success, so that's my objective with 78.

 

[robert teseo]

i,m currently set for 77, so that means 76 to 78

 

[ca1ore]

You have to play around with it. Depends a lot on how it reads temperature and how much flow you have through the unit. In my case, for example, the temp probe is inside the chiller, and flow through is on the low end of recommended. As a result, the chiller cools internally faster than does the main tank so I have set the ranco for a 3 degree spread (77 to 80). The chiller does not rapid cycle this way. When the tank is above 80, the chiller comes on until the internal chamber drops to 77, then it goes off. It has not cooled the entire tank though, so the chamber temp immediately begins to climb until chiller clocks on again. Been running it this way for a while and it keeps the tank pretty stable at 80. Obviously if your unit measures temp in the sump you'd not want such large setback.

Unfortunately my chiller is too large to be able to run it through my apex for redundant control so I just rely on a low temp alert.

 

[robert teseo]

it measures temp in the incoming water, it,s a teco. and I also do not have it connected to my apex at this point. I,m not sure the apex can handle the combo unit

 

[Ocelaris]

Thanks ca1ore, that helps a lot. I hooked mine up today through the Apex, as it's only a 1/4 hp chiller, but I forgot my ups was hooked up to that Eb8 so it did a little alarm! But what you said about flow and having it not short cycle is what I'm going to aim for as it's over sized and going through my uv which isn't ideal as they're pretty much opposites in flow requirements. But worked like a charm to bring the Temps back in line and now I can close my stand and remove that cheap fan!