Help!! Maybe re-scaping will help??

I have had an ongoing problem for close to a year with elevated nitrates and phosphates. I have tried everything that has been suggested; more frequent water changes, less frequent water changes (was suggested I was maybe doing too many water changes and wasn't giving the bacteria enough time), I upgraded to a larger skimmer, added gfo (tired other phosphate removers as well), reduced feeding (pretty sure the tank is underfeed now, as I've noticed my foxface isn't as plump as he used to be), added more flow to the tank to eliminate dead spots, upgraded from a RO unit to an RO/DO unit. Still nothing has helped. Granted my levels aren't sky high, but enough that I am always battling algae and high enough that most sps just flat out look crappy, if they don't die off that is.

Typically nitrates are between 15-20 ppm and phosphate is on the higher side of .25. Through trial and error, I've come to the conclusion it's the rock itself. I purchased 90% of my rock from a tank tear down sale. He had his tank set up for a ~5 years. Plus the two years I've had it. So it's going on 7 years. I'm sure it's pretty dirty and full of crap. I try to blow it out with a turkey baster every water change, but that only does so much.

My questions game plan is this. I've been wanting to re-scape my rock work for a while now (plus i have a dead fish somewhere in the rock work decaying which is just adding to my problem). What I was looking to potentially do during my next water change, is fill a brute can with the water from my tank and remove all the rock piece by piece and give it several good dunks and swishes in the trash can to really deep clean it and remove all that built up crud and then work on putting it all back in and re-scaping my tank.
Would that create havoc in the tank and cause a new cycle???? Thoughts and opinions?? I'd really like to be able to get into sps and really fill out my tank and not have to battle algae anymore. This is my last shot prior to a full tank tear down, and I don't think I'd be able to get back into it after a tear down.
(Sorry for the novel)

 

I have looked into them, as far as reading up on them and talking to a few people that have had them. The biggest issue I have is space. Under tank is already pretty tight, and not much room to add a scrubber. I've also looked at the in tank DIY versions, but with how my baffles are set up, I wouldn't be able to do one large enough to really make a dent on the total ~120 gallons.

 

I currently have a fuge with some chaeto (size of a large cantaloupe)


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It doesn't grow crazy fast, but there is always a good amount of noticeable growth


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It's currently at the point that I have hair algae and cyano growing on the chaeto.


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Currently it's a LED light bulb with the metal reflector. Ran opposite tank lights for 10 hours.


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Sorry for the late replies! Been hectic with work this past week. I started carbon dosing this week. Good 'ol Hawkeye vodka for the win!
@Buku, I'll have to look into switching out lighting! A gallon baggie every 2 weeks?! That's crazy!
@Sponge, I've thought about pulling out the rock and re-cycling it, but I'd like to use that as an absolute last resort. Rolling into the busy time with work, I'm afraid I'll just let it go and not be able to really focus on doing it right :-/
@hart, I don't actually have that much sand in the tank. I initially started bare bottom, but didn't end up liking the look so I added sand over the course of a few weeks. Just enough sand to cover the bottom really.
@F.D. Reefer, I think I have 2 turbos left. I have a mix of a few different snails. Turbo, astrea, nassarius, and some cerith

 

I actually have an extra T12 fixture and bulbs. Too bad it's a a large 4'er and won't fit under my sump

 

Was cleaning some stuff up last night and came across a 2' T8 fixture and bulb. I think I have enough room to retro fit it under my tank (after buying new bulb - no idea how old the bulb is). Think that will be better?