Welcome to the Forums Rob!
Lighting is obviously very important in a planted tank. Check out the
Lighting article for more info.
Bear in mind that a tank with such a large volume (180 US Gallons or so) will need less Watts per Gallon that stated for the same effect.
How much light you need will depend on the plants you want to grow. If you want to be able to grow anything then I'd aim for around 1.5 WPG of decent full-spectrum light with reflectors. With this much light you'll need CO2 injection. A pressurized system will be essential in a big tank like yours.
Personally I'd go for T8 fluorescent if I was on a budget, or Metal Halides if I was loaded (and willing to invest in CO2 etc.)! The Arcadia Luminaires are nice too but pricey, I'm sure you can get the plant tubes fitted if you shop around.
These tubes are ideal for a planted tank and are cheap (I've just ordered two myself).
http
/www.thearc.co.uk/catalogue1.php?cur...b_group1=Activa
If you wanted a low light tank with non-CO2 go for two tubes, up to six tubes for a high light tank where you could grow anything well (providing to have sufficient CO2 and other nutrients).
Personally I'd go for 4 x 58W 60" tubes ( total cost - £21.16). You'd have success with most plants with this much light but would need CO2 injection for best results.
Reflectors from here -
http/www.aquatics-online.co.uk/addtobask...tp=045&rets=149
Shop around for starters for the best price.
The pinned articles are a good source of info, I recommend reading the algae, lighting, CO2 and EI threads in particular if you intend planting heavily.
Please feel free to ask any other questions you may have, there's plenty of friendly experience on here.
Hope this helps and good luck with your tank.
Regards
George
