I have a 75 gal low light (3x 30w fluros) tank with about 50-60% plant
cover, and approx 100 small fish (good balance of varieties, including
bottom feeders, loaches, corys etc). The plants are all common varieties,
eg., java fern, java moss, elodea, amazon swords etc etc. Each week I do a
50% water change and add the following Seachem products: 35ml Excel, 3ml
Supplement, 4ml Nitrogen, 4ml Phosphorous, 10ml Potassium, 7ml Iron.
Filtration is an Eheim Pro II 2028.

No doubt many of you will be horrified at that brew, but I can assure you it
works, and the tank looks fantastic--terrific plants with moderate growth
and fish that are very happy and healthy. I'm completely satisfied with the
look, it's beautiful, just what I wanted. But ........

There is a small problem with algae. It's not serious, but about once per
month I have to trim some outer leaves off due to a dark green, dense algae
which forms along the edges of the leaves (and on the driftwood). I am
confident I don't overfeed (well, maybe just a tiny, tiny bit once in a
while), so I guess the algae is the result of overfertilising.

So my question is, which of the above ferts should I start reducing to try
to achieve perfection? I don't want to change the whole regime, because, as
I said, it works. I just want to tweak it a bit to reduce the relatively
minor algae problem. Thanks for any constructive advice.