Have tropical,planted tank,unusual size 99cm L x 42cm W x65cm D. 67.5 gallons. Have 2 t5 tubes 39w each. + 2 t8 tubes 30w each.is this too much light for the tank,lights on 8hours a day.? Mainly low light plants.would I be better off with just the two t5s ,maybe longer light period or switch to led
lighting. Any advice gratefully received.