Metal Halide

[beesnees]

hi all i have just recently purchased two arcadida 250 metal halide lamps of ebay, bargain at £3.20

my question is can you have too much light? they are being used on my juwel vision 180 atm. and it just seems to be a bit over the top, but due to my tank having a strengthening beam in the middle it requires a unit either side

regards andy

 

[N1z]

For your size no not at all. Maybe 2x 400watts but tbh people still have things along those lines but. Its mainly to do with the depth of the tank that you require higher wattages.

But generally 150-250 watts are used on all standard depth tanks

 

[beesnees]

thanx for that

 

[Colin_T]

The main problem you have with halides is if they are too close to the tank, then they can warm the water up. Make sure they are hung high enough above the tank so you don't feel any heat on the water surface.

The other issue can be if the tank has corals in and the corals have been kept under low light. Then putting bright lights on the tank can cause the corals to get sunburnt and bleach. Under these circumstances you should put the halides on for an hour a day, (in conjunction with the old lights) and increase the amount of time a bit each week. Start off with 1 hour a day and after a week increase it to 2 hours. Then a week later increase it to 3 hours, and so on. Once the halides are on for 6-8 hours per day you can turn off the old lights and just use the halides.

 

[beesnees]

The main problem you have with halides is if they are too close to the tank, then they can warm the water up. Make sure they are hung high enough above the tank so you don't feel any heat on the water surface.

The other issue can be if the tank has corals in and the corals have been kept under low light. Then putting bright lights on the tank can cause the corals to get sunburnt and bleach. Under these circumstances you should put the halides on for an hour a day, (in conjunction with the old lights) and increase the amount of time a bit each week. Start off with 1 hour a day and after a week increase it to 2 hours. Then a week later increase it to 3 hours, and so on. Once the halides are on for 6-8 hours per day you can turn off the old lights and just use the halides.

there is no actual fish or corals in my tank atm, there is only base rock and live rock, until payday
would i have this problem when buying corals from the lfs or could they go straight under the halides

 

[Colin_T]

most shops keep their corals under halides so there isn't normally any problems. The biggest problem is taking corals from under fluoros and putting them under halides.

 

[ben1987]

have you got them yet?
as lamps are usually just the bulbs? do you have the fittings and ballasts already?

 

[beesnees]

have you got them yet?
as lamps are usually just the bulbs? do you have the fittings and ballasts already?

i have every thing they are mounted to my wall and running on my tank now, it was everything, as i said BARGAIN

 

[ben1987]

chuffin hell..not bad


il give you a fiver for them

 

[beesnees]

chuffin hell..not bad


il give you a fiver for them

i did have to drive to Wales to pick them up, but at that price why not

 

[Crazy fishes]

"The biggest problem is taking corals from under fluoros and putting them under halides".

So how is best to achieve this. I am going from 2x 36W PC to 150 W MH. I was thinking of reducing the photoperiod to 6-8 hours from the usual 12 hours.
How does that sound??

Regards

 

[Colin_T]

Under these circumstances you can put the halides on for an hour a day, (in conjunction with the old lights) and increase the amount of time a bit each week. Start off with 1 hour a day and after a week increase it to 2 hours. Then a week later increase it to 3 hours, and so on. Once the halides are on for 6-8 hours per day you can turn off the old lights and just use the halides.

Alternatviely hang the halides well above the tank and have them on for about 6 hours a day. Then after a week lower them down a couple of inches. Each week move the lights closer to the tank until they are at their permanent position.
Make sure the halides aren't too close to the water because they will warm it up. Have your hand under the lights but just above the top of the tank. If your hands feel warm then the water will get warm and the lights need to be higher up.

 

[Crazy fishes]

Just sitting at my desk and looking across at the tank then suddenly realised I had a 36W PC unit sitting right next to me on top of the Rio 180. I have plugged it in and put it over the 24g which now has 3x 36W (118W) 50:50 PC. It really makes a difference and scared the $%&* out of the clowns, who hid in the hammer. Forgot to mention the clowns now host a frag of hammer coral which my urchin fragged for me. Anyway was think of using the extra tube until I go topless with the halide. Might make the transition easier. What do you think??

Regards

 

[Colin_T]

having the power compact on the tank will certainly help the corals now and when it comes time to having the halide on. They will get use to the brighter light and it will be less stress during the transition

 

[Crazy fishes]

My thoughts exactly, thanks for the confirmation Colin. I was thinking is 150W MH directly comparable with 150W PC? I know at depth of greater than 20" the halide is better but is the PAR appreciably different at depths less than this? Also in a tank that is 20" deep could SPS corals and/or Tridacna clams be kept with 3x 36W PC and if not why; what more needs to be added?

Regards