Your HC will suffer more being choked out by hair algae than from receiving less light. I would double up on that Excel daily and start doing more water changes. Manually remove whatever algae you can. This stuff really sucks. Your moss may die dosing high amounts of Excel, but the rest of your plants will love it. Honestly, I would consider just removing that moss. I'm seeing some dead spots in it, that's just going to add to your organics and feed the algae.
Other option - the one two punch (H2O2 + Excel).
Can you post a full pic of your tank please? Thanks
Heres a FTS, tank has seen better days
... please ignore the plants on the right, admist a iwagumi -> dutch style transition to try to increase biomass.
Your nitrates are some of the problem. Algae thrives in water with high levels of this form of nitrogen and the phosphates in some fish foods. If you feed a bit more like when you have fry in the tank, the uneaten food dissolves and adds to the problem. Some algae is a fact of life and some is a good water filter and supplement to your fishes' diet. Change more water and do it more often. A 20 G tank needs at least a 50 percent water change weekly. Twice weekly would go a long way in keeping added nutrients out of the tank water and will help control the growth of algae.
Thank you. I will try to increase the water change levels, I am currently doing it once a week but I will try to squeeze in another.
If it's just green hair algae and not mixed with rhizoclonium, the one-two punch will wipe it out. I have a moss tree in my tank and it became infested with hair algae, rhizo and BBA. My nitrates were also very high due to the organics in the water column. The moss acts as a filter pretty much, collecting all sorts of waste. I was successful with the one-two punch at ridding the moss of hair algae but the rhizoclonium came back a few days later. I got sick of dealing with it, so I just removed the whole tree and dunked it in a 5 gallon bucket of water and placed it in a dark room for 3 days. All the algae died after that and the BBA turned red.
My amano shrimp have finally went to town on the dead algae but they have also pulled a great deal of the moss out of the tree. I just crammed the moss in the branches without CA glue, fishing line, thread, etc. Glad I did, now i can just keep stuffing fresh moss in there as it thins out, as well as pulling infested moss out of there without hassle.
I have pretty much just accepted the fact that moss will be a magnet for algae when water parameters get the slightest bit out of whack or the substrate gets disrupted. I consider the moss expendable.
Thank you. Ive looked into the one two punch but havent done it yet. As far as I can see its just hair algae and maybe some BBA (maybe from the effects of raising the light? never had them before). I may gut the tree of all the algae / moss and start over.
Hair algae is 100% a problem of import. Manipulating conditions will not eliminate it. Even if you reduce it, it will always be lurking in the shadows, waiting to strike.
Temporarily relocate the livestock and treat with API Algaefix until all the hair algae has turned white and died. Otherwise you will be fighting it forever.
I will do this as a last ditch effort, the only tank I have is a 5 gallon and I dont think 15+ tetras would be happy in it
Glut (Excel or Metricide) treatment:
Stop the regular dosing of Excel.
This treatment may kill your moss, but the once-per-week treatment I have found to not harm plants normally killed by Excel. I suggest starting at 1.5 ml of Excel per gallon and, increase it by 1 ml / gal each week until all the hair algae responds.
This is only for hair algae. Other types, such as GSA and GDA, are not significantly affected by glut. For hair algae, itís a matter of hitting it with a sufficient quantity of glut and most people are terrified of doing this. I completely kill it within four days using the correct levels of glut.
The key is finding the right amount to do the job as a function of the biomass and to do it once a week ONLY until the hair algae no longer returns (via recovery of the plant balance). For example; due to my current biomass, I found (after three weeks of increasing dosages beginning at 1.1 ml / gal), that 2 ml / gal of Metricide in my 26 gallons of water was needed, which is the equivalent of about 3 ml / gal of Excel. It used to be lower when my biomass was smaller. Since plants love glut, they will consume a lot of the dose within a few hours, thus the need to find the optimal level to kill the hair algae over a ~6-hour period.
This is far, far, above accepted limits and people will tell me that I might as well detonate a nuclear bomb in my tank. However, not a single fish (wide range of community types Ė including corys), Amano, plant or BB has shown any sign of distress. I even have thriving anacharis in my tank, which melts under regular glut dosing but, again, it is the single dose that allows them all to withstand it. Regular dosing kills anacharis even at recommended levels. I should also note that none of my fish have grown two heads. The hair algae will turn the characteristic orange-brown in about four days, indicating that it has died.
Preparation: maximize oxygen. Glut is a reducing agent and will lower oxygen levels. At high doses, such as above, oxygen depletion may be high enough to be deadly to fish. I maintain a heavy surface rippling (two Hydor Koralia 240 GPH pumps pointed at the surface) all the time. In my case, this is enough gas exchange to compensate for any O2 reduction that may be caused by the glut. This only has to be done the first day.
I will play around with the levels of excel. I learned the hard way, I sprayed some excel on the algae covered moss during a water change, and it killed the moss and not the algae lol.
Currently dosing 1 capful a day, but I can try the once a week method and see if it changes. I appreciate your input!