You are focusing too much on adding stuff to the tank. That is the general approach on the US forums so that is what you think works best because everybody talks about chemicals, fertilizers, and "adding more". In reality you need to "remove more".
Your tank has an issue with waste. That includes the fertilizers you are adding (and now more of them). You need to first remove the waste as much as possible. That may or may not include reducing the excessive fertilization. The waste may not be visible but as you see algae grows for no apparent reason.
The first thing to do is to vacuum and change water so you remove visible waste. Do not overdo the water changes. You can lead your biofilter to crashing if you hit it too often with fresh, dechlorinated water. That doesn't sound not right but in real life it can happen. Best practice - change water every other day, no more than 15% of the tank volume. Premix the dechlorinator, don't use your tank as a chemical mixing vessel for the dechlorinator.
Next thing to do is to improve your filtration. That includes both larger biofilter volume AND better water flow pattern. You do not necessarily need higher flow. Depending on how you position the outflow and inflow you can have a tremendous increase in the efficiency of the water circulation. Best approach - direct the flow close and along the front glass only, the outflow is close to the surface, the intake pipe is on the same side as the outflow pipe. The intake pipe is a little above the substrate. The outtake pipe creates a slight ripple on the surface (that is very important because the surface plays a huge role in the processes in the tank).
The volume of your biofilter needs to be as large as possible. That Eheim filter is not going to do wonders for you. I don't know what size is your tank but the volume of the Eheim is good for about a 20 gallon tank at most. You can make it work though, even if it is small to start with. Get some pumice from any Bonsai supplier. Look for size of the grains from 5 mm to 10 mm. This material will serve as both biological and mechanical filtration media. So it needs to be placed in a mesh bag so you can take it out of the filter easily and rinse it in tank water every 2 weeks or so. No sponges, no active carbon.
The high CO2 will supress the biofilter. The mentality here is that the more stuff you add to the tank the better so most people put the pedal to the metal and go. Lots of fertilizers, lots of light, max. CO2. But fact is that high CO2 supresses the biofilter. That is why at night it is a good idea to turn the CO2 off and introduce air. Two reasons for that - you give the biofilter a break AND you help the plants do what they do at night.
Make sure that if there is little CO2 the lights are not running on full: If you turn the CO2 at night it will take some time for it to build up during the day (especially if the filter outflow is making the beneficial ripples on the surface of the water).
Make sure you understand what EI is. It is not about maintaining high levels of ferts in the water. Most people miss that "fine" point. It is about supplying the plants with whatever they need. ADA does that by providing a rich and active substrate and keeping the water void of nutrients (but they do add tiny daily dosages of ferts to the water). EI relies on loading the water with ferts that are food for both plants and algae. You decide who will get ahead if anything stops the plants from growing.
Plants taking care of everything:
Truth is if you make the plants grow well they WILL take care of all problems in the tank. The real question here is how to make that a stable, almost self-sustaining process. Your goal is to make the plants grow well, not to toil on that tank every other day out of necessity.
Yes, wait and see what happens after every change you make. Too many things at once and you will not know what was a good decision/action and what was a bad decision/action.