What might this be?

[SoonerFan732]

What is the brown looking substance in the three pictures below? The tank has been setup for six months and I just noticed this for the first time a couple of weeks ago.

Thanks!

Kevin

 

[EdKruzel]

It is possibly a layer of diatoms forming from excess nutrients in the water (silicates?).

The bubbles are simply trapped nitrogen escaping the system (but not quite getting away).

Watch your feeding habits and conduct a few water changes to balance out the system.
Also increase the current in the tank and ensure that it alternates.

Ed

 

[SoonerFan732]

I probably have been overfeeding the last month. I will use your recommendations.

How do you recommend setting up flow so that it alternates?

Thanks for the information!

Kevin

 

[EdKruzel]

The easiest way is with a couple of cheap 24hr timers that you can buy at Wal-Mart, HD, or Lowe's.

For a 75gal you may wish to have two powerheads in the center of the tank and pointing straight ahead or at 45 degrees outward that remain on 24/7.
Then one in each back corner but on the timers. Direct them at 45 degrees inward toward the front center which will cross current with the two centered back.
Mix the timers up so that they go on and off at different intervals all throughout the cycle.
Sometimes both timers are on and other times they're opposed.
This will keep the water currents moving in multiple directions and cut out any dead spots that can trap detritus and build up excess nutrients.

Ed

 

[SoonerFan732]

Thanks!

 

[SoonerFan732]

By the way it comes of very easily when I hit it with a turkey baster. Is that a mistake? Should I siphon it off?

 

[EdKruzel]

If you can siphon it, then by all means remove it with water changes.

Extreme nutrient removal/export is the best method for keeping a healthy tank.

Ed