How Many Watts For My Tank Please?

[tanyauk]

Hello! I already have 3x54W T5 tubes (162W), but as my tank is very deep, I think it is not enough. How many watts would be ok?
My tank is about 300 litres, thank you

p.s. I run CO2 pressurised system

 

[nry]

That's about 2 watts per gallon. Not too bad, how deep is your tank? Are you having problems with plants that leads you think you need more light?

 

[tanyauk]

thank you for your reply!
It is 75 cm deep! My Limnophilla is a bit leggy, that I think means it needs more light. I would like to carpet my tank with small plants like Glosso too...

 

[Dave Spencer]

Isn`t your tank over 400l?

4ft = 120cm.

120 x 75 x 50 = 450 litres.

This means you would need 200W.

 

[tanyauk]

Dave, when I calculated water volume I didn't count gravel, rocks volume, so 300 litres are just water without decor, so 200w then? thanks!

 

[Dave Spencer]

The WPG rule is a very general one. As you rightly suspected, depth will have an influnce on the amount of light reaching the bottom. There are other factors such as the tanks footprint to take in to account as well.

I am no expert on lighting, but I wouldn`t have thought that emptying half the water from your tank means you need half the WPG, although the depth has obviously been reduced. The WPG rule is not a linear function, with bigger tanks needing proportionally less WPG than a smaller tank.

Quality of light is a very important factor, especially if you want to carpet Glosso. What tubes do you have?

Dave.

 

[Themuleous]

Dave makes very good points re the depth and the light quality. Is it a rena aqualife tank? I'm going to get the 150cm version for my next tank.

Anyway to the lights, there is an interesting article in my sig by the finches which compares Amano's tanks in his three natural aquarium books, according to that you need around 200w for a high light tank.

Sam

 

[tanyauk]

Thanks guys! It is Rena tank you right! I have t5 tubes with pink colour (for plants). I think my plants do not consume CO2 at this light level because my fish seem not happy and slow As soon as I stop CO2 they active and happy again. I had smaller tank before and everything was ok, but I upgraded to this bigger tank and I use the same luminaire. I bought one more luminaire for my fish tank, same one, so hopefully things will be better!