Algae can be caused by several things, but generally lighting isnt such an issue, even though its the first thing people say when there is an algae problem!
Theres a few things to check first.
What are your Nitrate and Phosphate readings?
I know you say you are doing water changes, but how often, and what size?
What size is your tank?
Sometimes simply not having enough filtration or water movement is enough to set off algae bloom.
Now you say you have cut back on feeding, but what are you feeding?
Obviously you know algae needs light to grow, but bright or dim, algae will still flourish if the conditions are right.
Excess nutrients and slow moving water are the most common causes.
You dont need a bristle nose in your tank, the Cichlids alone will clear the algae, as they are natural grazers.
So, try to raise the water movements in your tank, add a phosphate remover, and put some new carbon in the filter.
Water changes are great, if your tap water has no nitrate, but tap water CAN have high nitrate content at times, so you need to test that.
As you have Malawis, generally you should be feeding vegetable based foods, which dont make to much mess, so check the protein content, you need as small amount as you can get.
I feed shelled peas, lettuce, frozen malami mix which is mixed algaes and a small amount of shrimp, and tetra pro vegetable, and hikari malawi pellets.
My lights are on 12 hours a day, and I have a large window by my tank, and I dont have any algae problems.
So, you need to look at the water movement and nutrient levels, and there Im sure you will find the root cause.
Good luck.
