I have a Biocube 29, and live in South Florida and I experience alot heat in my tank and alot of evaporaton. I'm using a make shift chiller for my tank which is a $8 fan blowing over the open rear lid. While this seems to work great and prevents my tank from overheating at temparature of 84-86 degrees and allows my tank to maintain an average temp of 76-78 degrees.

As it stands today I'm losing almost 3/4 gallon of water a day due to evaporation and suffer the flutuation of salinity and continue filling the tank with RO water on a daily basis.. This does not happen when the fan is off and the lid closed, however having the tank at 86 degrees is not a healthy option for the tank. I have two options.

1. Invest in a relaible Automatic Top Off System (JBJ ATO) a Tom Dosing Pump and RO container at an approximate cost of $140.

3. Invest in a good used 1/10 HP or 1/15 HP chiller with a pump at an approximate cost of $280-$300.

With Option 2, will allow me to close the rear lid and have very very little loss of water due to evaporation.

I would opt for the chiller if you can afford it. I don't trust ATOs and unless you're not around your tank frequently it isn't very hard dumping a little water into the tank time to time. The lid and using a chiller will dramatically decrease your evaporation rates.

Even just the chiller if you have an open top tank the chiller will help a lot in evaporation.

autotopoff.com top-off for $40, 5.5aga for $10, cheap pump for another 10...or opt for the $50, dual float switch version for added safety

I've seen this page but the floats look rather large to fit in chamber three of my biocube 29. Plus I like the idea of an alarm for an empty reserve tank.

yeah. an ato system doesnt have to be anywhere near $140.

They also make smaller versions, a nano sized one as well. the big one fits in my solana no prob.

and i dont know about you, but I check my tank's equipment everyday, just when im spending time in it. A simple opening of a cabinet door too see if the reservoir is low is pretty simple. I fill up 5.5g every week with out falter

Its not a matter of checking my tank everyday, its a matter that my RO unit in downstairs in the garage and I like to take the occasional weekend trip without having to bother friends and/or family to add water every single day. I have an automatic fish feeder that I use for weekends trips.

understandable, but like I said, i fill up 5 gallons each week, nothing that 3 days would drain. and if you're out of town...what difference is an alarm gonna make if you're gone

Well the alarm would be more for my wife, she works 12 hour shifts at night then sleep during the day. If the tank sump and reserve was to run low while I'm at work at least she will know its low when the alarm goes off. I had more of a chance to look at their website and its not very intuiative or informative. Look at inTank's Media Basket website and Nanotuners website wihch allow you to select your tank model and then list all the parts required for the most popular tanks. They should allow us to select our tank and they have all the needed listed.

makes sense. I think the website is straight forward. these ATO's arent tank specific, just position specific. the sump model allows for added vertical positioning thus alowing for a lower water level in the sump. the tank model sits very high to the rim, thus keeping the water level up high.

All I know is that I own 2 of these, on 2 different tanks and i have had no problems. if you dont want to spend 250 on a super fancy litre-meter or tunze, this is a great option. i'm sure other people can say the same. best of luck in your search

I'd go ato. Extra float switches for reliability. I've had 2 chillers fail on me, the first just about nuked the tank, the second is still down, but the controller (another couple hundred) saved the tank by shutting a bunch of equipment off and turning on fans.

How would a chiller eliminate evaportation??? ATO for evaporation, a chiller for over heating issues. 2 completely differant things. I would concided if you are running lots of fans to keep the tank cool this would increase evaporation. Adding a chiller would removed the need for the extra fans=more evaporation. But no matter what you are still going to have evaporation.

I did not say it would eliminate evaporation, I said "very very little loss of water due to evaporation". In the first two weeks the tank was set up I only had to replenish the evaporated water once. After two weeks I was finally able to find replacement batteries for my digital thermometer and found out the tank was running way too hot at 86+ degrees. Currently I still lose about 3/4 gallons of water and my tank runs closer to 80 degrees.

I've already decided to go with the ATO however not the JBJ system I first thought about. Now my plans are much greater as I'm seriously considering getting the Reek Keeper Liite Plus system and floats. From what I understand the RKL+ will control the pumps for an Auto Top off system and help control my tank temperature by automatically turning ON/OFF my cooling fans based on a temperature probe. The RKL+ will also eliminate my Coral Life Digital Timer as is can be programed turn On/Off my Day and Night lights. I was also about to purchase the JBJ Wavemaker to alternate my two Koralia Nano 425 pumps, which is also not needed as the RKL+ can control those pumps as well. the RKL+ comes with a pH probe to monitor the tank's pH.

Fans and an ATO. I cool my 100G w/2x250w MH and 2x140w VHO with fans only in Phoenix but the ATO is a must. I finally sold my 1/4HP chiller after it never ran even once for two years unless I ran it manually to exercise it. The tank stays 79-81 year round with two 4" computer fans in the canopy and a WalMart clip on over the sump. Properly placed and sized fans work wonders.

Short answer: ATO, it will also help to keep your tank more stable and help your skimmer (if you have one) at a more constant level, helping it to pull better skimmate.

+1 to all who say ATO

Chillers are pretty awesome if you have extreme temps inside your house, but ATOs are something that I couldnt live without in reefing.

Even if you can constantly top off you will still have larger variations in salinity than if you were using an ATO. Plus an ATO tops off to pretty much the same place every time, where there can be user error doing it by hand. Finally, just like turning on your lights every day sucks so people use a timer, having an ATO really makes your life so much easier.