2 AI Prime's 20l and sps

[Cannoy]

Will 2 primes over a 20 long put out enough light to grow SPS? I already have the tank setup and I have the old Primes not the hd's.

 

[Crabs McJones]

Will 2 primes over a 20 long put out enough light to grow SPS? I already have the tank setup and I have the old Primes not the hd's.

I would imagine so, but the only way to be 100% sure would be to put a par meter under them and see what they're putting out. But two on a 20 should be ok ;)

 

[Cannoy]

I thought it should be, but just wanted to get an opinion. And I would like to use a par meter but I dont know anyone with one, and they're a little too expensive for me.