Is chiller is a MUST for tanks using MH lights?

[joe]

For a 6x2x2ft tank with 2x150W MH lights, is it a definite must for a chiller if temperature is to maintain below 28 degress celsius? Wanna seek opinions while I plan for such a setup.

[kadios]

Hi Joe!

I have been waiting for someone with that kind of setup so that I can witness personally the hotness of MHs especially in a large tank. It seems to me so far PLs are the better option if chiller is not used especially in tanks larger than 4ft. So I guess the best bet are PLs in a large tank with fans. To use MHs in large tank, you can almost be certain that chiller is indispensable. I have been holding back my large tank project because I cannot settle the issue of MH hotness without using a chiller.

Cheers!

[theodore]

28 deg C (+/- 1 deg C) is acceptable for most plants though some species do prefer lower temperatures. I'm able to achieve this temperature using 4x 8cm 12VDC fans for my 4ft tank with 2x 150W MH pendants.

I've heard of people out there using 2x 150W MH on a 6ft without relying on chillers ... and fans.

[joe]

Hi kadios, me too. So dats why I am asking for comments here. Especially from those who are having such a setup now.

[Simon]

I'm running a 6x2x2 with 2x150 MH... no complaints of the water temp... but the room is warmer now :P. The photo period is 6hrs

[Goh_TM]

Hi Joe,

it depends on how high u hang the MH away from the water surface. Next is if the ballast is interal or external ballast.

Normally, MH can easily increase the temperature by 3-4 degrees. Given the surface area of the water that allows the fan to blow across, it should be able to pull dwn 2-3 degrees.

I tend to use the below for rough estimation of tank temp.

Tank water temp w/o anything on = 30deg
MH = +4deg
Cirulation pump = +2deg
Fan = -3deg

30+4+2-3= 33deg

Personally, I would go for a chiller if I can afford. As Singapore got hot/cold spell ard the yr, there will be temp flucation if using fan. During certain mths, the fan might not be able to cool the tank.

A chiller is not only to bring dwn tank temperature, it is also to maintain the water temperature in tank throughout the yr.

Cheers!

Goh_TM

[joe]

Hi Simon, how's your water temp? Care to post a latest pix of your 6ft??

[Simon]

[quote:849ab3f2e7="joe"]Hi Simon, how's your water temp? Care to post a latest pix of your 6ft??[/quote:849ab3f2e7]

no more than 30 degree.. cause, the lights only turns on after dark.. so even on the hottest days, its still okie. of cause if you can afford a chiller then by all means, but its an optional equipment. unless you keeping moss I don't see a need for one

[MikeKoh]

My tank size is 6x2x2. Lights by 8x55W PL lights. Used to have 4 fans blowing at the surface to achieve temp at 28. Now I am using Artica 1/5HP chiller and temp set at 25 celcius... my plants are happy, fish are happy...

http://www.arofanatics.com/members/m...ns20thmay2004/

[GreenTea]

how much does a chiller cost? i was thinking of using 2x150 MH in a 6x2x2

im afraid that the water will be too hot... especially mine is an arowana tank so, my top needs to be covered...

[loupgarou]

you can't use mh in covered tank, you need at least 1 ft of clearance space between the glass cover of the mh light and the tank top/water surface, otherwise, water splashed will lead to the glass cover weakening over time and exploding one day ..

[vinz]

Chiller for a 6'x2'x2'? Prepare to fork out 1.5 to 2K$.

Your tank temp will also be affected by how well ventilated the room is. MH (lights and "ballast") also warm up the air in the room. This warmth eventually transfers to the water. If the room can be well ventilated, you have less issues. Other then encouraging evaporation, the fans should also be setup to move the warm air around the lights and above tank water away from the area.

Some MH lights made for aquariums come with both FL and MH bulbs. Set the FLs to be on for 10 to 12 hours. The MH should then come on for only 4 to 6 hours in the middle of that.

While you can get good temps with fans for the large part of the year, when the hot months come round, the temps can really go up and if you are unable to keep the temps down, then all the hard work you put to keeping the plants healthy and keeping the algae away is lost. I got fed up with that after 2 years (just using fans and PLs), so I finally gave in and got a chiller. The results are so much better. The plants now grow much better overall.

OTOH, there are people I know who are lucky enough to be able to situate their tanks near windows, and have family members at home all day and thus not have to close all the windows when they are at work. They do quite well with just fans.

Slightly off the original topic... a chiller in the same room will heat up the air in it too.. which well, heats up your tank too (not enough to bring the temp back to without chiller, but certainly contributes in some ways). If you are going to get a chiller, if you can install it outside (i.e sheltered balcony) or in a well ventilated area of the room. In the worse case, You fish will be in "air-conditioned" comfort, but you, the one forking out the money, has to contend with coming home to stuffy, humid home and family members (especially the "home minister") complaining about it.

[schema]

In my own experience,

I have been using 150w x 2 MH(12 " from water) & chiller combi all the while, my chiller turn on about 4 times per day (estimate)

But when I change my MH to 6 x 55w PLLs(8" from water), my chiller seems to turn on more often!

Any rational to this? Now I am adding a fan to cut down chiller usage frequency.

[Nicky]

[quote:635ba05d32="joe"]For a 6x2x2ft tank with 2x150W MH lights, is it a definite must for a chiller if temperature is to maintain below 28 degress celsius? Wanna seek opinions while I plan for such a setup.[/quote:635ba05d32]

I used to maintain a 6ft (with 3x150W MH) with 2xAC fan. On hot months, I need to top up as many as 10 bottles (1.5L each) of water every day to make up for the evaporation.

I believe it is possible to maint the 6ft tank about 2 degree below the ambient temp with fans.

[LLC]

Just to share my experience on MH lights.

I am using 2 x 150 watts MH (external balast) on my 6x2x2 tank. The lights are 18 inches above the water surface. Photo period is from 1pm to 10pm. 4 (12x12cm) DC fan is used used to cool down the tank. They are on for 20 hours each day. Rest for 4 hrs from 2am to 6am. There are 3 canister filter running on the tank. (heard that filter increases the temp)

The max temperature during the hot season is 29 deg (before lights on) and 31 deg (before lights off). And during the recent cool season the temperature is 26 deg (before lights on) and 27 deg (before lights off). The reason of the lower reading maybe due to the thermometer is place in a shady area at the back of the tank and the window in my balcony is always open. This makes my house much cooler.

Plants wise, they are doing quite well but of cause not as good as those with a chiller running in their tank. Currently there are 4 types of mosses growing in my tank : Java, Erect, Taiwan and weeping mosses. All are doing well. Erect moss used to be brown in colour but it is OK now, may be due to the lower temp these day. Plants that grow out of the water surface will get burnt easily.

I got a friend doing repairs on chiller. This is what I got from him. Nowadays, there are some chiller working on lower HP and the specifications stated that it is able to cool down to a certain temp on big tank (e.g 6x2x2). This is not really true as the termostat is located at the cooling coils and hence register a lower temp by the chiller display. According to him, to effeiciently cool down a 6x2x2, min a 1 HP chiller is needed.

Hope the above info helps.