Ok Simon everything seems to be ok here from the stats you post but obviously something is not right, when you dose too much trace this can sometimes cause problems but 5ml 3x per week is not overdoing it by any means, but if i was to change any one parameter i would change this for now, i would cut right back dosing trace for now dont dose any more until the water change and after that i would dose only a tiny amount if any at all, the reason im suggesting this is because we dont know whats in the substrate it could be adding to the problem but i dont know for sure, but excess trace can cause problems that i do know and it could be coming from the substrate. So for now i would cut back dosing trace, do this for about a week and see if it makes any difference.
Green spot algae is usually caused by lack of phosphate but you will also usually see it on the glass of the aquarium, i would dose a little bit more phosphate eack week and see if this improves, the existing green spot will not disappear from the extra dosing it will only prevent fresh algae from appearing, i usually judge by looking at my glass if my phosphate levels are low and would up it accordingly, but im surprised you are seeing it TBH at the levels you have, if i dose 1 ppm po4 3x per week i never see green spot algae, but everyones tank is different, just up the levels a little bit and wait and see if it improves.
I would continue to dose phosphate and nitrate and cut back on the trace for now, maybe there is something in the substrate dont forget its a brand new product and hasnt been road tested by hobbyists as such.
Up date the thread in a week or so and let us know how its going but i would water changes as normal and keep the co2 steady and obviously keep removing the algae as much as you can.
