[Scyry]

I have 3 Amazon Swords in my tank. All three are around 12"-16" tall with a lot of leaves and in general looking good. I've had about 3 leaves on each plant develop holes.

What could be causing the holes? I dose with Excel twice a week, and have no CO2 or anything else.

 

[Regenesis]

Hello,
It looks like a possible nutrient deficiency. Are you using root tabs with those swords? <Swords are heavy root feeders>

 

[wetworks]

I think it may be your plecostomus. I caught my plecos eating some of my plants and it looked just like that. It looks like they just eat the outer hard layer of the leaf and leave the inside exposed. Try putting some fresh veggies or some algae wafers in the tank for the pleco.