help everyone

i have had crystal clear water and slow good algea growth in my tank but just wondering what would cause brown algea to arise in the last week and a few bubbles are attached to the rocks not a lot of brown and bubble algea but want to nip it in the bud right away so where should i start it is due for a water change and i am doing that today but what other things should i check in the refugium / sump, the sump at the same time has got a touch of the red algea in it as the DT started to get the brown and bubble algea. i am checking all the chemicals today also but will bring results to meeting and any ideas on other stuff to clean or check would be great. last week when i checked water parameters they were spot on and salinity is .0123 so what could be the problem so i can correct it???

I went through a 3 week period of brown algae and it was due to the fact I had mixed some tap water in by accident (rinsed without thinking and thawed out my frozen food in a water from the tap) and the other part until I changed my RO source was possibly a bad RO filter from wet pet and critters. Since I have installed my own RO with clean filters I have had no brown algae and all my parameters have been good. I run my salinity at .026, PH 8.0-8.2, and my ammonia/nitrates have been nil (or at least the lowest color on the chart). Also I added the refugium and moved my skimmer down there and only empty that once every week or two depending on my feeding habits.

Check RO filter and water source would be my first idea.

I'm going to assume you mean your salinity is .023 rather than .0123... but other than that you obviously have nitrate and phosphates. Even if your tests read 0, we know they're there because the algae needs them to grow.

I would look at the following to improve the situation:

1. Feed less. If you're already not feeding too much then look at other options.
2. Buy a TDS meter and check all freshwater before mixing your salt in. It should always read 0 (you should do this anyways!).
3. Add a GFO reactor. GFO will need to be switched out often but is used very often because it works very well. If will remove phosphates, nitrates will still need to be removed through water changes.
4. Improve equipment. Skimmer and powerheads. Skimmer to remove more waste before they break down into nitrates and phosphates, powerheads to keep waste suspended so it doesn't settle on the bottom or into rocks.
5. Biopellets. I've read enough good about them that I'm starting them up for sure. They're used to remove both nitrates and phosphates. They are a new product and require a lot of research to implement.

thanks alot guys and that is the culprit the water i have never used tap water and i had run out of ro water to top off my return tank in the sump and i had to add water so i used tap with a water nutrilizer or what ever that stuff that suppoto make tap water ok but that didnt work but will make sure to keep an eye on my water stock. and will adjust the powerheads it is just kinda hard to keep sand from flying off the sand bed and to not get dirrect current on the corals?

1. how often do you feed?
2. what are biopellets and where do they go?
3. should i bump my salinity up to .025?
4. what is a gfo and how does it work?

Place your powerheads high in the tank and angle them up towards the surface a bit. That'll help. :-)

1. Every other day or so. I feed carefully also. I feed the fish until they're less active going after the food, and I only add a few pieces of food at a time to make sure it doesn't just fall to the rocks.
2. Biopellets are a solid carbon source and have a porous surface ideal for denitrifying bacteria. Like I mentioned, they take a lot of research before being considered. They go in a Solid Media Reactor.
3. Salinity is good in a range between .021 and .025. Bumping your salinity will not effect your algae. Many people run higher salinity so that their salt mix has higher cal, alk and mag levels.
4. Granular Ferric Oxide. It soaks up phosphates like a sponge and then needs removed. Most put it in a reactor such as the TLF Media Reactor. If you're not running Carbon I'd run that in a second reactor as well... it helps soak up some other things that might get into the water. Helps your water clarity and removes any bad odors the tank might have.

1. how often do you feed? every other day my frozen shrimp and creel, but flake food once daily for the fish. I add microvert and zooplanton also twice a week for my filter feeders.
2. what are biopellets and where do they go? I have not used these or read up on them.
3. should i bump my salinity up to .025? I was running .023 but found some of my verts and soft corals liked the salinity higher. Agree with Matt .021-.025 should be good.
4. what is a gfo and how does it work? I used to use a GFO/carbon combo media when I was running a container pump, but found I didn't need it after switching to refugium as my tank is pretty balanced and not over stocked if anything it is under stocked still.

My guess is that the tap water caused the algae. Most tap water is loaded with phosphates. Phosphates = Algae. There are water conditioners that make tap water safe but it won't remove the phosphates that cause algae. My tap water is loaded with phosphates so I have to change my RO/DI filters as soon as my TDS gets any reading other than 0. Salinity has no effect on algae but 1.025-1.026 is a good range for a reef tank.

thanks to all i am doing a water change today with ro water and thanks so much to all for the help

Never use anything but RO water. There is enough of us around you can usually get some to hold you over till you can replace filters or whatever the case may be. The tap water was definately the issue.