cavyroo said:
strontium, iodine about every 3-4days..and essential elements once a week.
This is fuel for the fire and you should consider not using them. With a pre existing problem, additives of this nature will only add to the available nutrient macro algaes need to grow, especially the iodine. Water changes are your best means of control for trace elements.
Your lighting will only be a concern if the bulbs are not being changed every 10-12 months based on how long you run them. The length of time run will not really impact the life of the algae so much as the growth rate. The longer the lights are on the more it can grow but even if only on a few hours a day it will still get enough to sustain itself. I run mine for close to 12-14 hours a day.
Added nutrient is still the main concern as can be what's bound up in the rock and substrate. Keep in mind that even with P removing products (resins/pads), they can only help with inorganic forms of P. The organic forms bound up in bacteria and such must be released first before they can be removed in that fashion. Skimming is the only thing that can help with organic forms of P but again, it's not going to happen quickly.
You mention using RO water but does it have a DI attachment? RO alone will not remove P and certain other elements. Only the DI stage can do that. What is your TDS reading?
Best thing is a long term attack, short term solutions will only yield short term results. Large regular weekly or 2x weekly water changes, heavy skimming, using the P removers won't hurt any, using foods that are low in P like home made blender mush and frozen preparations. Steer clear of freeze dried, flake and pellet for the most part. If using Nori, switch alternately with frozen broccoli as Nori is absolutely lousy with P. Pre soaking foods and draining them before had to remove the P also helps. Throughout this though, be sure the foods remain as nutritious and use vitamins where possible.
Animal control is usually hit and miss. Best urchin species for this is Diadema's (long spine), I have had decent success with Mespilia globulus as well. Fish, nudi's and crabs are usually not that effective, especially where the algae has grown too long. It will often just get ignored. Manual removal is key in beating this along with nutrient contro, and proper water flow. When you pull it out, siphon along at the same time so as not to spread it further. Take note while doing this how much debris is trapped within the algae especially close to the rock, you'll most likely see a decent amount. This is where the algae will get a good amount of it's nutrient from. In keeping it short, you also prevent it from accumulating needed nutrient. It also allows the animals specifically added to do a much better job.
How's the chemistry of the water? Alk, pH & Ca?
For the polyps, get a new soft bristled tooth brush and ever so gentley remove the algae. Not all at once, just a bit at a time and use even light pressure. You basically just want to pull the algae through the bristles so it tears free, not actually rub the polyps. Use a Turkey baster or reposition/add more water flow to prevent detritus accumulation and help starve the algae of needed food sources.
Cheers
Steve
