Looks a lot like diatoms(brown algae)... how new is your tank? This is a common algae noticed during some cycles(usually in new tanks). List all your water test results and we may be of more help, though.

     Jason

There is some macro algae in the tank, but nothing substantial. My tangs appear to be grazing on any new growth.

I do feed my fish a variety of food and fairly often, but only as much as they will eat immediately (10-20 seconds).

I had done it that way becuase if I fed them a 'normal' serving, half of it goes in my overflow before they eat it. So I only feed them as much as they will clear the second it hits the surface.

I feed them three small servings daily:
- Flakes in the morning
- Alternate Blood Worms or Brine Shrimp at noon
- Rotate various frozen cubes at night

If I'm only feeding them as much as they can eat immediately, would that cause overfeeding issues? My fish act like I'm starving them when they do get fed.

BTW, I won't need many snails, probably need crabs more. Of course, that was one of the things you were going to help me figure out.

improdigal wrote: I feed them three small servings daily: - Flakes in the morning - Alternate Blood Worms or Brine Shrimp at noon - Rotate various frozen cubes at night

WOW!

Adam

Wow as in 'too much' or Wow, I'm obsessive compulsive?

I brought this practice over from my Fresh water tanks. I found rotating their diet gave them much brighter colors and shinier scales overall.

I think we will all agree that rotating their diet is the best practice.

I think Adam's WOW response was due to the amount of food being feed.

I guess my next question would be, can I overfeed them rotifers??? I'm trying to build up my 'bug-base' so I added a whole quart of them to my tank a couple days ago.

The aquarium told me that might cause an Algae bloom, but I need one at this point, I can't get algae to grow faster than it is eaten by my sea urchin (see nitrate problem above.

Although feeding your fish as much as you are is probably not hurting them, it directly correlates with you nitrate problem.

I would stop feeding altogether for a couple of days and then start feeding them a little each day.

I would also recommend a large water change ASAP to take care of the immediate nitrate problem.

What types of filtration do you have on your aquarium?  How much live rock?  What type of sand bed and how deep is it? etc.

I have a sump system under the tank (40gallon) with the skimmer/heater/bioballs in the sump. I'm planning to setup a refugium with my old 25 gallon tank as soon as I can move out the FW fish in it and get someone over to help me set it up.

In the tank itself I have about 100lbs of LR, 4' crushed coral substrate.

Bio balls could be a major part of your problem... pure nitrate factories. IMO, slowly remove the balls(20% per week) until until gone.

     Jason

I'm going to cut back my feedings to a small serving once/day and see how that helps.

What purpose were the bioballs supposed to serve (ie. will I have other problems when I remove them) and why do they cause a nitrate buildup?

My quick take.  The "wow" was for both regularity and quantity.  I would say that I am one of those people on the far side of feed your fish a ton.  I feed my feed about once per day when I first get them, but after a week or so, I go back to my regular feeding schedule.  Typically, I feed my tank about once every 3 days. 
Jake on the other hand is a "a hungry fish is a healthy fish" guy and he feeds his tank about once every 3 weeks. 

Your variety is great, and similar to mine (except my staple is the food we made at the meeting) but that is a lot of food to add to the tank.  Remember whatever goes in the fish, comes out on the other end.  That could be a big source of nutrients for your tank.

Adam

Bio balls are the area in which bacteria builds and where nitrites and ammonia, through chemical reaction, produce nitrates(IMO, the nitrate factory). I do agree that macro algae is an awesome ingredient to any sump. LR is also a great asset for filtration/denitrification. As well as a good skimmer. I don't intend to offend with my opinion, though. It just goes to show that there's no "one way" to have and maintain a successful captive reef.

     Jason

improdigal wrote: 100lbs of LR, 4' crushed coral substrate.

Wow my tank isn't even 4 feet deep. (Sorry couldn't help myself.)

All this time I thought that Adam liked to feed his fish often.  I guess I'm right up there with Improdigal when it comes to feeding fish. I don't feed on a schedule he does, but I feed religiously everyday.  1 small cube of homemade fish food goo.  Some days I may add cyclopeez to that or later in the day feed golden pearls, brine shrimp or flake.  The extra does not get fed everyday, but probably 3 times a week or so.

I got the impression that Adam drops a little bit of something in the tank evertime he stops to look at it.  Then again, sometimes I get the impression that he doesn't stop to look at it all that often so maybe that stands to reason.

<<<<<<<< Feeds his fish 3 times a day with no problems. Good filteration is key to your feeding habits I feed my tank like crazy

but i also have a huge skimmer and 100Gal sump/ref

hehe...thanks everyone for all the input. I think I'll cut back on feeding, add my refugium (I don't have one yet) and then go from there. Although I will miss feeding my fish all the time. They keep looking at me when I come in the room like "daddy, why don't you feed us anymore" It's only been 2 days and the nitrates appear to be going down already.

wsinbad1 wrote: improdigal wrote: 100lbs of LR, 4' crushed coral substrate. Wow my tank isn't even 4 feet deep. (Sorry couldn't help myself.)

Always gotta have a comedian in the crowd. hehe

(yea I caught that after I posted it, DOH!)

My only question would be, is there any reason NOT to have both the bio-balls, ls, lr, and the refugium.

That is a topic that has been discussed often.  There are scientifically debatable reasons to remove them.  And there are many people who can testify to the fact that their nitrates dropped after removing the bio-balls.  But right now they could be providing a good portion of your nitrification.  So if you remove them do it slowly (a few balls per week or something like that).  If you don't feel comfortable removing the balls, then install the refugium and get it going.  If the nitrates fall then you're in fat city.  If the nitrates are still high then reconsider the use of the balls.  Just my opinions.

Alternatively, some people have claimed quick denitrification success by simply completely submerging the bio-balls (or bio-wheel).

jfinch wrote: Alternatively, some people have claimed quick denitrification success by simply completely submerging the bio-balls (or bio-wheel).

Well my bio balls are almost completely submerged all the time anyway. So maybe I was using them wrong anyway ;-) HA HA HA

When I use bioballs I use them in a "tower" of sorts where water cascades down over them keeping them wet all the time but not submerged.  Similar idea to the biowheel.  It's a very aerobic environment where nitrification reins king.  You can go to Marine Aquatics to see a MONSTER version of what I'm talking about.