seeing brown algae

[jnguyen4007]

I have a 30 gal tank with a 20 gal long tank that I used as a fuge and a sump. For the past couple of weeks, I've been noticing what looks like brown, stringy algae (?) on the sandy surface of my tank. Is that what it is? If it is brown algae, is it because of phosphate? If it is, then will a phosphate reactor take care of the problem?

[der_wille_zur_macht]

You need to give us more information - age of the tank, equipment that's running, livestock, feeding and maintenance schedules, etc.

[jnguyen4007]

I have about 40 lbs of live sand in the main tank (30 gal) and 10 lbs of live sand in the fuge section of the sump. The main tank has about 50 lbs of live rocks that been curing for couple of months before i put them into the main tank. In fuge, I have chaeto in it as well.

In the main tank, I have 1 soft leather coral, 1 torch, 3 sps, 1 yellow tubinaria, 1 candy cane, 1 small green zoa frag, and couple of monti frag. I have a bunch of different snails (nassirius, conch, etc). There are also several hermit crabs and a fireshrimp. I have a pair of juvie false percs, 1 midas blenny, 1 mandarin, 1 neon goby and a purple firefish.

In the sump, I have a Tunze nano doc skimmer with a small pc light running over the fuge section for most of the day. (I have not changed the bulb on the PC light in quite a long time. Not sure, but I'm wondering if this has anything to do with it as well.) The fuge light is on from 6 AM until midnight.

As far as lighting goes in the main tank, I have it an Aqua light pro, that has 2 dual arctinic light and 1 150W 10K MH light that's mounted on legs about 4" above the water. I have the arctinic lights on from 12 PM to 12 AM. The MH light on from from 2 Pm to 10 PM. The moon lights are on from 12 AM to 12 PM (opposite of the arctinic light schedule.)

I premix the frozen food of cyclopeze and mysis shrimps with tank water and store it in the fridge. I make enough to last about 3 to 4 days. Using a syringe, I feed between 1 and 1.5 tsp of food. Once in a while, I feed them with dry ora pellet food. Feeding time is usually about an hour before MH light goes off. I also target feed the yellow tubinaria once every couple of days with a small amount of food. I target feed the torch and the candy cane once a week, again with a small amount of cyclopeze/mysis mixture.

My ammonia is 0, nitrite is 0, nitrate 0. pH aroun 8.4. Ca in ppm around 400. Alk value in dKH around 11.8. Magnesium unknown and phosphate unknown. I don't have a kit to test them at this time.