40g Reef Tank

[Aquascaper]

This is my tank that has been going about 8 weeks:

The fish were 'donated' by a friend who shut his tank down and the majority of the LR was taken from a 150g established tank that had been running for 2 years.
There is 3 powerheads and a Berlin Classic skimmer running on the tank as well as mech filtration in the filter chamber + an empty external filter.
I have since added some inverts and soft corals and thus need to upgrade the lighting as the twin tubes aren't giving enough IMO.

My question is this: I have a 400w MH with a 20,000k bulb which i know is a little overkill but it was a very good deal What I want to do is remove the unit from its housing (it is an industrial metal casing) and use a reflector. This will hopefully help to keep the temperature down and make it easier to mount above the tank.
Will this cause masses of light spillage aroung the tank or are these reflectors quite effective? Would I be better building a custom hood and using fans to cool the lights?

Any advice/suggestions would be appreciated

 

[Navarre]

I have a very similar light to yours (400w in a white metal case)

You can remove it from the case and place a good reflector around it .... However, you will need to put a layer of glass between the bulb and the water surface to stop the High UV from damaging the corals. I had a friend do exactly the same thing and within mere hours he had lost over £5000 of prime colours Acros

I would advise you to build a box to house the reflector and slot a layer of glass (it needs to be special glass that blocks UV light) under the bulb. Use fans to extract the heat if needed.

 

[Great Lakes]

A note on the UV. Is it a single or double end bulb?

SE bulbs do not give off the UV rays as do the DE bulbs.

That being said, I would definitely build a canopy. This way you can house fans and additional lighting. Additional lighting you say? Yes, I would continue to use your current lighting and just run the Halide for say an eight hour photoperiod.

GL

 

[Navarre]

Now thats something i didnt know! You learn something new in this hobby no matter how long you have been in it!

I have a single ended Bulb in my 400w (my 150w halides are double ended). BOth systems have glass to protect them but the Single ended doesnt give off the UV? is this a design difference then?

 

[Aquascaper]

Thanks for the advice guys

The unit is a single ended mogul fitting and at the moment has a glass plate in front of the bulb but i was going to get a glass plate for the top of the tank anyway to help reduce evaporation (i currently have a plastic one but think that may just melt ).
I am planning to keep the T8 tubes running but mount them down the lengths of a wooden frame which will sit on top of the tank with the glass plates mounted on the frame, the MH will then be mounted above the glass 'window'.
I was only planning on having the MH on for around 4 hours per day with the T8's being used to gradually increase/decrease the light level. I was told by another reef person that this would best simulate natural daylight as, due to light refraction through water, natural reefs only get 3 - 4 hours of direct sunlight per day (when the sun is right overhead).

 

[Navarre]

Whiulst its true that some reefs only get a shorter period of sun per day, if you visit these "sites" the corls are not as colourful and tend to be more a dull borwn coour as the coral produces far more aleag to absorb the sunight. if you increase the sunlight and visit reefs that have more sunlught then you will see these coral with intense colouration. Most hobbyiests want a showpiece tank with vivid colours etc. this means increased lighting IMO.

I would not put the halide son for less than 8 houyrs per day ... my own 400w are running 10 hours per day and i have some fantastic colouration.

If you want then you could change the "K" on the bulb to perhaps a 20 k (i like the 14k personally) this will give the corals less light but increases their colouration.

 

[Aquascaper]

20k bulb is the one i'm using

I will increase the time that the MH is on as you suggest as I to want a 'showpiece' tank with as much colour and life as possibe, my only concern is having the MH on while i'm not in so it will be limited to about 6 hours.

Thanks again for the advice.

 

[Navarre]

Cant you put the halides on a timer? Mine doesnt have a built in timer but i purchased a timer plug and it works fine. My halides now come on from 11am and shut down at 10pm

 

[Aquascaper]

I've got no problem with putting them on a timer it's just that they get quite hot and i'd hate to start a fire while i was out