lighting recommendations

[Dave]

Can anyone give me an idea how much lighting I should have in my tank.

Its a 48x18x21 about 300l. I currently have 1 tube @ 38W. Im not sure what type of tube it is. But would like to know what I need.

Although I have no Plants at the moment I will soon be putting some in, as for the types, well it depends what looks nice at mt lfs (Sorry don't know much about plants either! ) )

I was thinking of having a moonlight for my ghost knife fish, but don't really want a load of heavy Transformers at the back of my tank. Can anyone help?

 

[EddieW]

Dave,

A (very rough) rule of thumb is 2 watts per gallon for plants with low light requirement, three to four for plants of medium light requirements and 5 watts per gallon for plants that require heavy lighting.

Your tank is about 66 gallons (UK) so using this rule of thumb you would need between 132 and 330 watts of lighting depending on the plants.

There are other factors to bear in mind as well. The light requirements of your fish - if they prefer lower lighting levels you need to take this into account and buy appropriate plants. There is also the absorbtion issue - the deeper the tank, the brighter the light needs to be to penetrate to the bottom.

Another thing to look at is the type of lighting - you say you have one 38w tube. I would guess that this is a standard 42" T8 fluorescent tube. I assume you are using a good reflector on this to make sure the light output is all going into the tank.

If your hood will take it you could add a second, third or even fourth light fitting but this would add the additional controllers which you don't really want - although the advantage of this is that you can use seperate timers to switch the lights on and off over a period of time to simulate dawn and dusk. The total you will get with this is up to 152w.

If you were to switch to T5 tubes you could change to two Arcadia Twin 54w T5 controllers which would enable you to use four 54w tubes giving a total of 216w. Again with the two separate controllers you can bring the lights on gradually.

A third option is Compact T5 (called power compacts in the USA). You could fit two 22" dual compact T5 units side by side each with 2 55w tubes, giving a total of 220w - it would be difficult to bring these in gradually as one end of the tank would light up before the other.

The final option is to go for metal halide lighting (expensive!) as this is very powerful. For example you could get a 110cm Arcadia Pendant which would hang over the tank instead of the hood, this could contain 2 x 150w MH lamp and 2 x 30w fluorescent actinic blue tubes each type on it's own timer. This gives a whopping total of 360w when everything is on. The cost of this type of lighting is in the region of £500.......

Hopefully there is some info there that will be of use to you.

Cheers, Eddie

 

[Dave]

Thanks for the well detailed reply EddieW. its gave me alot to think about, and plenty to research, Im not sure what the lighting requirements of my fish are! To be honest I didn't know there were any ) Never mind, you live and learn. I quite fancy the idea of the Arcadia twin 54W, the're about £55.

I'm going to be making a new top for my tank soon, one that will match the base, so Ill have to think of a suitable reflective material for the interior.

Ok thanks again, just have to find £110 now best not tell the missus