+ Reply to Thread
Page 1 of 3 123 LastLast
Results 1 to 10 of 27

Thread: Brown algae in the tank

  1. #1

    Join Date
    Apr 2010
    Location
    usa
    Posts
    13

    Brown algae in the tank

    So I have a 680 gallon tank. I'm running an ATS with 2 screens that are 30x12". There are 4x22w CFL bulbs at 4000k with 2 more 55w flourescent bulbs. I run it about 7-8 hrs/day. My nitrites are zero and the nitrates are under 10. I clean my ATS weekly. The green algae that's growing looks a little slimy and dark. There are only 9 fish in the tank totally around 50".

    The problem I'm having is I'm getting brown algae in the display tank. It's covering most of the bottom of the tank where the sand has blown off and is bare. Why am I growing algae when I have a scrubber and my water parameters are good? Am I not putting in enough light into the display tank?

    I have been feeding more recently and the fish are getting a little bigger. But with 680g and another 150g in the sumps I would think it shouldn't be affected that much. I don't do too many water changes since I figured the ATS should minimize that. But lately I've been changing about 25% / week.

    Any thoughts?

  2. #2
    Administrator
    Join Date
    Oct 2008
    Location
    Santa Monica, CA, USA
    Posts
    10,104
    Welcome.

    Gallons and waterchanges do not matter. The problem is your very weak scrubber lighting.

    How much are you feeding?

  3. #3

    Join Date
    Apr 2010
    Location
    usa
    Posts
    13
    Quote Originally Posted by SantaMonica View Post
    Welcome.

    Gallons and waterchanges do not matter. The problem is your very weak scrubber lighting.

    How much are you feeding?
    Really? Each of my CFL are equivalent of 100w incandescent and the 55W CFL is like 200w. When this thing is on it's like a solar flare.

    I was feeding only twice a day on weekends. On weekdays only once a day. I've since cut it back to once a day.

  4. #4
    Administrator
    Join Date
    Oct 2008
    Location
    Santa Monica, CA, USA
    Posts
    10,104
    Each 30 X 12 = 360 square inch screen needs a total of 360 real watts, preferably in a 2-sided configuration, for 18 hours a day.

    Yours has 4 x 22 watts + 2 x 55 watts = 198 watts, a little over half of the minimum. And less than half of the hours. So at best you have 1/4 the photosynthesis you need.

  5. #5

    Join Date
    Apr 2010
    Location
    usa
    Posts
    13
    I made a mistake on the amount of time. I'm running it from 6p to 1p the next day. So 19 hrs / day.

    Let's talk in terms of lumens. Each 22w bulb puts out 1500 lumens and the 55w puts out another 3900 lumens each. With 2 two sides screens that's still not enough?

  6. #6
    Administrator
    Join Date
    Oct 2008
    Location
    Santa Monica, CA, USA
    Posts
    10,104
    Ok so about half the minimum photosynthesis you need.

    Not nearly enough lumens.

  7. #7

    Join Date
    Apr 2010
    Location
    usa
    Posts
    13
    If I'm only making half of what I need I can't run it 24/7. So the only way is to increase the lumens? I could have swore I calculated it correctly. Maybe I didn't rough the screen enough or have enough flow.

    At some point it would cost more in electrical energy than just changing water.

  8. #8
    Administrator
    Join Date
    Oct 2008
    Location
    Santa Monica, CA, USA
    Posts
    10,104
    Two screens of 30 X 12 is 720 square inches, which is sized for 60 cubes a day.

  9. #9

    Join Date
    Apr 2010
    Location
    usa
    Posts
    13
    I've added more light but the brown keeps increasing. I've heard that scrubbers dont remove silicates and the brown feeds off of silicates. Is that true? Is it possible that I don't have enough flow?

  10. #10
    Administrator
    Join Date
    Oct 2008
    Location
    Santa Monica, CA, USA
    Posts
    10,104
    Nothing to do with silicates.

    Even with enough light, If you are not feeding at least 30 cubes a day, it will only grow a thin brown because there are not enough nutrients. You never said how much you feed, so there is no answer to how big the scrubber should be.

+ Reply to Thread
Page 1 of 3 123 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts