when fans are not enough


Reefing newb
The system is all pretty & new per the signature. Chemistry is near perfect. Lighting is a 4 tube 36" TO5 on the refugium & a 6 tube 48" on the main tank. Those lights are a lot of heat .. I had no idea the heat load would be so high. I decided on these for the future coral in the main + variety of plants for the ref. I have been using fans but the temperature variation is from 70 to 85 deg F. The tank temp follows the room temp with steady state ~3 deg higher. (I feel like I am preaching to the choir here.) This temp range is too extreme for almost any of the coral that I want to get to. Putting all of this out there before people say just do this or that.

People in AZ have hotter temps, but that's dry heat, right? Here in CT air temp ranges from 20s to 80s but so does the humidity. Evaporative cooling was fine with the previous setup, fish only, fluval, and in a total A/C house.

Is this not a case for a chiller?:question: I have searched the net + forums but do not see much discussion out there about life with a chiller. Yes, I have read, here, that chillers are not so common. but there must be a few.

To that end, what brands are reliable? Probably easier to find out what isn't. Any unique features that are worth considering? It seems for this number of gallons appropriate sized chillers range from >$500 to about $1K. Are there any heat pump versions? I am an engineer:beer: so it is entirely within my purpose in life to scope this out with a spread sheet. But, surely someone has beat me to this?
For one you can reduce the Lights in the refugium to just 2 t5 bulbs, To be honest you don't even need that just get the power save compact swirly bulbs, just get 2 with the dome fixture and make sure the lumens are 65k and they would be fine. I have 1 of them and it grows my macro like crazy. and only 10 watts.

Also To keep the temps in check you heater should be doing its job to not have it drop so much should be like a 78 no lower than 76 depending of preference. I like mine higher up and so do my corals so I keep mine about 78.6f all the way up to 82 at times but usually keep it under 81. If you aim the fan to blow across the top of the water it should help bring the temps down and like I said before the heater should keep it from dropping to much. only thing with the fans is your evap if going to go up so you will need to add water more often.

If you get a chiller it would solve the problem definitely but it is more costly, just set the chiller at the temp you want it say 79.8 f then set the heater at 78 and you should be good. I Usually see the JBJ chillers I think there used a lot and work good.
Yes, I had taken the heater out & was planning to place it in the sump ... but had not as yet. I had thought that the really cool nights were over for the season.
That's a huge range in temperature. If it varies, you really don't want it to vary more than 1-2 degrees in a day. Here's my recommendations: (1) get the heater back in the tank (or sump) to help stabilize the temp from falling below 78. (2) Invest in a controller. I held off on doing so for a long time and am so glad I finally did - its totally fixed the temp swings I was having in my smaller tank. I went with just the basic ReefKeeper Lite but for a 90g tank I think I'd go with the ReefKeeper Elite (or if you have the money look into the apex). The base model of any of these will control your heaters and fans and you can add more powerbars and modules with time as you need them or have the money for them. (3) As for the high temps, do you have a glass top or canopy on your tank? If so, start by removing them so you get better air exchange. What kind of fans have you tried. A cheap table top fan pointed directly at the water surface should be enough. If you have the fan plugged into the controller then it will come on and help cool the tank before the temp raises up so high. You can also plug your lights into the controller and program them to shut off if the temp gets too high. Another thing you can try is raising your light fixture higher if possible. Bottom line, I think there are better options than a chiller. I've seen far too many chillers overheat and make problems worse, and they are expensive and consume alot of energy. I know people with huge tanks in rooms that get a lot of sun and heat and they are able to control their temp with just a fan, so I think you should be able to as well!
I keep my 90g cool with two computer fans and a large fan I mounted on the wall behind it. Both fans blow across the water and the large one blows from back to front over the lights. When I touch my lights I can't feel any heat at all. The fans lower the tank by up to 5 degrees! Anything past that I have the a/c in the window is set to 82 degrees just in case. No controller no chiller just fans I plug in before I go to work.
I have 2 10" fans blowing on the refugium and a 3rd 10" a few feet away aimed across the ref . I am sure that I could get more cooling if I added fans to the 90, but with the fish only I had 3 fish jump out and then there were the escaping snails (nerites I think). The first time I discovered an escapee, I stepped on it bare foot ... that took a moment to comprehend. For an instant I thought D@mn cat fished it out, realizing the next moment that was very unlikely. I am pretty sure that he got 2 of the fish after they had flipped out in the middle of the night. I spent the next several months covering all possible gaps around the cover.

Therefore, the main tank is covered tightly. The ref is open. The other part of the equation; the increase in the electric bill from January to July is over $300/mo. with 80 deg on the aquarium floor. I heat with nat. gas. I don't know exactly how much that bill will increase in going from 80 to 75 (room temp) ... but it sets a good budget and is a factor. Of course chillers use electricity also.
I have a JBJ Arctica that is fabulous. Here it can get well above 100 in the summer time. I have it controlled through my Apex as well as my heater. My tank stays between 78.5 and 79.5 year round. The chiller does not run that much since I have a pair of fans in the canopy as well.

If you decide on a chiller, get an in-line and NOT a drop in.
What model Apex? It controls the fans, chiller, and heater? And not the lights, right?

What model chiller?
I have the Apex full model. It controls everything, lights, pumps, power heads, skimmer, bio-pellets, chiller, heater........

My chiller is either 1/5 or 1/4 HP, I honestly do not remember which it is. But it is running on a 120 gallon system with no issues.