Please help
 

Can anyone tell me what this stuff is growing on my rocks? i been doing water change after water change and still wont go away!! any help would be great! my water prams are:
salinity is 1.025
phosphat 0
cal 440
alk 9.9
mag 1290
ph 8.1
water temp 78.5
nitrate 0
ammonium0
nitrite 0
The tank is just over a year old now

Algae
 

Pics are so blurry, can't tell. Google bryopsis does it look like that?

Looks like brown snot. Moves around in the water from the power heads

I can't see it from your pics, but if it looks like brown snot, it might be brown slime algae. Brown slime, from what I've read, is dependant on iron. SeaChem cuprisorb in an old handkerchief in the filter appears to fix it.

here is a little better pic

Look up Dinoflagellates.

Do you have a TDS meter to test the water you use? RODI or tap?

i been using ro/di since i started my tank. And about 6 months into the tank i have been dealing with canyo off and on too

And have you tested it? I was getting RODI from a grocery store for 6 months and when i bought a TDS meter checked and it was 2, and then checked the system at home I picked up recently and it was 5 until the filters were flushed and new resin added.

yep tds out is always 0. i sometimes wonder if my led lights are the problem? i did my own from rapid led and wonder if i have the wrong color spectrum. i have cool whites royal blue, and uv and green

What percentage is your Green of your total LED count, and what percentage are you driving it/them?

Same question with UV :biggrin:

i have a total of 4 green and 4 uv and run them at 15%. and i run my whites for 8 hours and blues for ten. blues are around 80% and whites around 30%

Okay, well I don't think that's it. (those spectrums in really high intensity can fuel some algae growth, and red also (let's just say that I had some 'fun' with some LED's in the past, and my snails had some work to do))

I have used cool white + royal blue leds from RapidLED a year ago on a smaller nano without issue, so you are likely okay there, and I ran 5 whites and 7 blues at 100%.

algae
 

This algae looks familiar and shows up in my tank on occasion. In fact I have some in my tank right now but it's starting to disappear.

This might be a long shot but are you running a calcium reactor? If so, you may need to dial it back or better yet, just use kalk for a while. When running the reactor, effluent should go directly to the skimmer to remove excess CO2. This made noticable difference in my tank.

Get a silicate test kit and measure the fresh made saltwater. I don't think the TDS can detect silicates. Until you know your water is free of silicate, stop the water changes for a while to see what happens.

Use phosphate free carbon and replace it often. Also use GFO. Although your PO4 test shows zero, the rocks may be leeching some. I used lots of carbon - like 2 cups for 200gal. to remove dissolved organics.

Try to cut back on feeding - this one really helped me. Also, remove any filter socks or sponges from the system.

And, if possible, remove the rock and scrub algae off - in a separate container of saltwater. This way, when it dies, it wont add the nutrients back in the water.