The bulbs are definitely trash now.
Raising pH above 7.0 with water changes will convert any ammonia, if present, from non-toxic ammonium to highly toxic ammonia. In addition, the water parameters, hardness, total dissolved solids, and so on have drifted so far from that of replacement water, that a large water change may shock and kill livestock ("old tank syndrome"). For safety's sake, water changes should be no more than 10% and performed every few days; the amount can be increased gradually over time. An ammonia and pH test kit would be helpful too. They seem to work well past the expiration date, at least in my experience, but no guarantees.
Of course, either new bulbs or water changes will drastically
alter the balance of what was almost a closed ecosystem. No telling what will happen.
Are you willing to commit to essentially starting from scratch, and spending some serious time with this tank? Otherwise, just invest in a good metal blade aquarium scraper (if it's a glass aquarium), or an original Mr. Clean Magic Eraser (if acrylic, no fragrance or suds when Eraser is wet), and learn to live with the GSA.
You might also try dosing some phosphate, but without knowing what's really in that old water, there could be a ton of it already; and other nutrients have simply gotten so high that the phosphate can't effectively be absorbed anymore (have seen it happen).