I donít know if high silica causes problems. Several years back people believed high silica was the reason for having algae but later it was dismissed.
I believe silica was largely dismissed because glass contains silica as well as sand and gravel. Furthermore most of the concern was specific to one type of algae, Diatoms. Diatoms are a type of algae that protects each cell with a shell of silica. So the theory was that silica cause diatom algae.
Since many tanks have substrate with silica and the glass contains silica all tanks should have diatoms which isn't the case. Furthermore SiO2 is not soluble. As a result most including myself dismissed it. But I later learned two things. SiO2 that makes up glass and most substrates is indeed not soluble. But other forms of silica Are Soluble
Your water report shows you have a lot of silica dissolved in your water. If your algae is a type of diatom then you have two choices to reduce the silica content, Switch to a different source of water or filter out the silica before you put the water in your tank. I have read that phosphate removers remove silica from the water. So if you put your tap water in a bucket and use a pump to circulate the water through a phosphate remover and then use that water for your water changes diatom algae might die out. Prefiltering your water with a phosphate remove may be the easiest solution to reducing silicate
I don't know what the white flakes you see are but maybe that is silica.
As to the rest of your water report your water appears to have sufficient calcium, magnesium, sulfur, and chloride which means you shouldn't have to worry about these nutrients. Your tap water also has copper in it due to copper pipes. Copper is another important plant nutrient. So 5 of the 14 plant nutrients. Just monitor your water GH and if necessary add a GH booster to compensate for the seasonal changes in your water.
Your water report also shows substantial amount of manganese and boron. But the range suggests that when rain water is enough there may be no Mn or B in the tap water. Most fertilizers tend to have enough boron. but some may not have enough Manganese. Now if you use GH booster that contains manganese it might help compensate for the seasonal loss of Mn. Seachem Equilibrium is the only GH booster I know of that has manganese in it. Most of the time you probably won't need ito use the equilibrium but in wet weather when the Mn, Ca, Mg levels might be lower it could help compensate for the seasonal changes in Mn in your water.
So overall your water looks good except for the silica. But is silica the cause of your current algaeproblems, I don't know. Another possible cause of your algae problem could be due to the Seachem Flourish you are using.
Regarding Seachem Trace, I looked at the label and all the elements in there are some 0.000000 something %, I am sure this elements are contained in my tap water. The report doesn't show some of them because they have never been tested but considering it's river water most likely the elements should be there especially in such minor volumes.
Your water is most likely river water during the winter and spring and then probably well water or imported colorado river water. Yes there are a lot of zeros in listed on the bottle. Don't assume your tap water has these nutrients! While I was using Seachem products in RO water and I frequently had nutrient ddeficieencies and only intermittent plant growth. Before I gave up on sachem I had worked through a nitrogen, phosphate, Ca Mg, and iron deficiency and then I was stuck. Plants were still not growing. Seachem flourish does list a lot of nutrients on the label but many are at such low levels that plants really can't use them while algae can. Seachem Flourish is poorly balanced. You might want to try a more concentrated fertilizer. Such as Trive from Nilocg.com or Easy Green from aquarium coop.com.