How many lights would you use for a 450l 65'' long tank?

Fairly heavily planted.

With or without CO2?

And you mean 65 inches, as in 5.5ft/1950mm?

aim for around 1 wpl, but anything from .5wpl will work.

so just add up the wattages of whater lights you use

I reckon though, if you're doing pressurised CO2, I'd go for 2 150W metal halides. deepblue has them for $200ea

Its more like 1651

Can you get tubes longer than 4 foot?

So f not I will need 11 tubes to get 1 watt per litre

or 6 tubes to get .53 watts per litre?

Id rather not go to co2... yet...

AFAIK 4 foot 1220mm is the longest tubes you can get.

T5 would be best but T8 is the easiest to get parts for and cheaper. I'd go with two double 4fts to start with, then add another double if you need the extra light. 4ft tubes are 36Wea I think. 6500K Daylight tubes are around $8-10ea at an electrical wholesaler or bunnings etc dont give off much heat at all and no drama if it gets wet.

btw T8 is your normal thickness fluoro, T5 is thinner and gives off much more light, but harder to get bits for and the bits are more costly.

I wouldn't go MH unless you're prepared to go hardcore with planting, as there are a lot of downsides, but it certainly is the best for plants by far.

What are the downs (out of interest)?

Do you call this hardcore http://www.fnzas.org.nz/fishroom/scalar ... t4866.html

Nah thats just some light planting mate

Thats along the lines of what I want.

oh and how high is the tank? lighting will depend alot on that factor. For example, if your tank was 3 foot high, you would need some crazy lighting to reach the bottom plants, but if its only 1 foot high, then you hardly need anything.... Start with 2-4 tubes, and see how it goes, but you will want pressurised co2 later on, and you will want more light. Just give in and go MH 8) :lol:

I reckon though, if you're doing pressurised CO2, I'd go for 2 150W metal halides. deepblue has them for $200ea

ask steve (jetskisteve) he will sell you a 150W mh cheaper

I think that could be done without going crazy, but by hardcore I mean injecting CO2 heavily and ferts etc and making the plants pearl.

Anyway downsides:

- they use a lot of power, smallest is 150W

- they concentrate in one area, unlike T8/T5 which spreads the light evenly

- they get very very hot

- due to the heat sometimes when splashed the glass can shatter on the light (although its supposed to be heat treated so it doesnt)

- they can't be seated on the top of the tank due to heat and light concentration, need to be held above, most people hang them from the ceiling.

Upsides:

- much more intense light

- deeper penetration so your grass plants will grow hardcore, something T8/T5 isn't good at

ask steve (jetskisteve) he will sell you a 150W mh cheaper

Yea definately

Yea definately

Noted

yeah thats were i got my MH good price 2!

its 500 mm deep.

Valinseria(sp) isnt a grass is it?