Based on the size of your tank (height mostly) I would say you're in the low-medium light category...just my opinion though. A par meter would be a much better measure to judge the level of light your plants are getting. Also in the first picture there is only one LED fixture? If that is the case your lighting is definitely inadequate for a planted tank with any plant that requires medium or high amounts of light.
Anyways my point being - if you fertilize as described by others, my concern would be that the plants aren't able to grow fast enough to utilize all the ferts because the light isn't intense enough. To put it very very simply, plants utilize 3 things to grow (again not an accurate explanation but it works well enough here):
2) ferts (macro+micro)
If all three of these are at optimal levels, you will not have algae problems. The plant growth will be maximal and if conditions are correct (fert/co2 level/intensity of lighting) there will be no excess of nutrients for algae to become a problem. Of course you will have small amounts of algae growing in your tank (like in a natural setting) but no nuisance algae/takeovers. BUT, if just one of these is too low (light for example), it will act as a bottleneck to the plant growing process, and the growth will be slower. In addition, since the plants aren't using the other 2 elements to their fullest capacity, those will be in excess in the tank (ferts/co2 in this case). These excess elements will be used by algae to grow, hence why it is important to find a balance.
- Low light, fertilizers, no co2: Algae because plant growth stunted by light/co2
- Good light, fertilizers, no co2: Algae because plant growth stunted by lack of co2, LOTS of algae this way
- High light, no ferts, no co2: Algae, not as much as above
- Low light, no ferts, no co2: (ultra low tech) Not much algae, but slow plant growth. Throw in some anubias/moss balls and you have a very easy low tech algae-free setup...only low light plants with this setup.
There are more combinations but they all follow the same reasoning. All 3 elements need to be in balance for optimal plant growth and minimal algae save for the ultra low-tech setup mentioned above.
Sorry for the long response. I just feel that lighting is too overlooked as an aspect for algae when it is usually the root cause. If you have the right lighting your plants can grow without the need for co2 and ferts, the growth will just be incredibly slow, and you won't have too much algae to worry about. Obviously some plants cannot be grown successfully without a good balance of those 3 elements, but usually the beginner plants (i.e. anubias, moss balls, moss in general, etc) can be grown in a low tech setup with low intensity lighting. Plants that would need high lighting are usually of the smaller leaf variety (carpeting plants for example).