I'm sorry to hear your having such a difficult time. Besides reiterating Ndrwater's post, here's what I would do. To start my primary method for dealing with nuisance algae is using
steel straws to siphon off the algae and a couple short spine urchins (
Just like Hawaii did). If you didn't use some ocean sourced live rock I would add some even if it meant taking ut some of your existing rock, see
Aqubiomics article here, beside beneficial microbial stuff the cryptic sponges will help process the Disolved Organic Carbon DOC, carbon dosing) released by corals and algae. If possible, I would get some water from a well established reef system that has not had any issues for a year or more and do one or two water changes with it.
BE PATIENT! You're shifting the microbiomes in the water and corals and it will take time. The algae in your system is dumping DOC into your system that is negatively affecting your coral, making it difficult for your corals to compete and promote the autotrophic microbial processes beneficial for them to thrive. Aquabiomics test will show changes in the water happen quickly but shifting the processes and equilibrium throughout the ecosystem will take time.
Stick with 10% weekly water changes. Doing more, from what I've seen over the years, has diminishing returns for the labor involved. But water changes are ESSENTIAL as that is the only effective way aquarists can reduce both hydrophillic and hydrophobic "junk" in porportional amounts (skimmers only remove a portion of the hydrphobic and are skewing microbial counts). Lastly, some will siphon off algae and run it through a filter sock to conserve water, this doesn't remove the DOC and may actually concentrate it when it's added back to the system, in light of how this DOC causes problems I would not do it.
A final note, don't think bright colors and fast growth are the goal. Healthy corals, depending on species, can have fast growth and/or bright colors but fast both can also be indicators of problems.
Here's some links to check out.
"Coral Reefs in the Microbial Seas " This video compliments Rohwer's book of the same title. Used copies are available on line and it may be free to read on Internet Archive. Both deal with the conflicting roles of the different types of DOC (carbon dosing) in reef ecosystems and how it can alter coral microbiomes. While there is overlap bewteen his book and the video both have information not covered by the other and together give a broader view of the complex relationships found in reef ecosystems and are an excellent starting point to understand the conflicting roles of Dissolved Organic Carbon (DOC, aka "carbon dosing") in reef ecosystems.
Delbeek Molar Ratios
Changing Seas - Mysterious Microbes
Microbial view of Coral Decline
Nitrogen cycling in hte coral holobiont
BActeria and Sponges Jones
Maintenance of Coral Reef Health (refferences at the end)
Optical Feedback Loop in Colorful Coral Bleaching
DNA Sequencing and the Reef Tank Microbiome
Richard Ross What's up with phosphate"