the manual work portion is missing in fixing this tank. I know its hard when the volumes are not nano level, but in the end you have final say over what colonizes your rocks and sand, and the waste you store. the work it takes to require compliance from your tank is irrelevant, the ends are 100% attainable. taking indirect action only is the cause of your problems. adding a clean up crew is an indirect action, they're for preventing invasions not removing them, that's for us. Its true you can wrestle with any number of parameter changes (indirect action) or grazer additions or lighting additions and possibly win. but that's a waiting/hoping scenario and its not the same as simply making that tank comply by Monday. You may have broken down the tank, but there are restoration moves left out that we show in tank breakdown threads, and the wastes your rock holds is a primary source and the algae needs to be killed during your work, not just mowed down.
predicted source of nitrate> Id be very curious to see a quick cellphone vid of this 10 second activity: film you reaching down into the sandbed, lifting up a handful from about halfway in the bed, then drop it down. if the resulting drop is cloudless that's awesome
if it clouds, like every other sandbed that runs this test, then you literally can see your source of high nitrates and the feed for that algae. choice time
you can also do this confirming move: use a siphon hose taped to the end of a wooden dowel...insert down to bottom of sandbed and siphon out some heavy water. *let it sit for 48 hours* then test for nitrate. I bet its double your topwater, or unreadably high. off the kit levels. the wait must happen you can't get an accurate reading without waiting 48 hours on the sample because that N is in different form than it is in your topwater. it has a whole protein complement and allowing 48 hrs for further breakdown reveals potential along with actual nitrate measures.
the things you are adding to the water are to compensate for places waste is directly being stored if that helps any. if we change your storage of waste, we drop your nitrate. direct work action is what removes the storage zones. the rocks when plugged with algae cannot expel their own waste (live rock makes waste/live/put some in a white bucket of sw for two days and check back on the waste pellets at the bottom) so they become a nitrate pump and their porosity drops. hand killing the algae restores all that, slowly, time to get started imo.
if your tank was mine it would have a new sandbed or at least correctly rinsed and reused current bed or even more popular no bed at all... all the rocks would have the algae killed in one setting, not just scrubbed off, then tank restored with a 100% water change Id pay the lfs to truck over. the reassembly protocol would be opposite to current mode... no more places to store waste. lighting would change, that white intensity dropped even more and blues upped.
if water actions don't resolve, lets add your tank to our reboot tank threads if you want to wrestle it back into compliance. they're all skip cycle reassembly setups, hard work but a shiny new tank by Monday. that killer UV will shine after a tank workover like that precedes the install
