Big light on a small tank

[cooperturner]

So I have started a small 40cm long tank that's 25litres.
I've ordered a light online bu it won't arrive for a week, I have already got micros swords in my tank and I'm using dry start method.
While I'm waiting for the light can I use a 3ft fluorescent light on the tank?

 

[tomtom14]

Yer should be fine.