brown stuff on the walls

[surgeon67]

I have a 170gal Marine aquarium (reef in progress, 7 months old). I have had good success with the growth of live rock invertebrates, coralline algae, and fish. recently I have had heavy growth of what would appear to be brown algae on the acrylic front of the aquarium, as well as the acrylic cover and opaque back. The snails make a dent, but cannot remove all of it (they leave corrugated trails through it). The "algae" is VERY hard to remove from the walls, and seems almost calcified. The magnet will NOT touch it, requiring LOTS of elbow grease several times a week.
WHAT IS THIS STUFF, and how do I control/remove/prevent it?

Another small problem: I have hundreds of ~1mm tube worms growing on my acrylic walls. I don't mind them, just not on the viewing surface. How do I prevent them from growing there?

[steve1s]

You will find that the hard algae is the regular diatoms that accur in the tank naturally. If left to long or after the snails go over it, the algae will become much harder. Easiest way to deal with it is to remove it daily.

The calcerous worms are spirorbidae worms, very harmless and a good sign of water quality. There is no way to prevent them really except to try and keep constant water flow on the glass surface. It will help prevent them from getting hold, but will not eleiminate them completely.

[Pineapple House]

I agree all the way with Steeve.

But, a few questions should be asked to find out why it's growing so much. Just curious, but what's your nitrate level? Phosphate level? WHat lighting do you have? How long are your lights on? What fish do you have?

As for the spirorbidae, they will grow everywhere. Although the best way is to srub the glass daily to prevent them from holding on :)

PH =)

[Pineapple House]

BTW- Welcome to reeflounge, hope you enjoy your stay!

PH =)

[surgeon67]

Thanks for the info so far. Here are my tank vital statistics:

Lighting PC 96w x 3 fixtures, timed for 11 hrs/day sequential
Nitrate 10ppm
Phosphate <0.25
ammonia 0
nitrite 0
ph 8.3
temp 76 (regulated with chiller)
fish 1Regal tang, 1 purple firefish, 1 banggai cardinal, 1 brittle star, 1 sand sifting starfish, multiple hermit crabs and snails, 1 cleaner shrimp.... the remainder died recently, and I suspect a mantis shrimp is the culprit (a trap is on the way)... but that's another issue.