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Discussion in 'General Discussion' started by pistol, Sep 8, 2016.

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  1. Built a diy down flow scrubber lit both sides with cfl floods. Went through a diatom phase for a couple weeks then green algae started taking over, algae got about 1/2 in thick after another couple weeks at which time I scraped it off and rinsed the screen with new salt water. Scrubber continued to grow green algae and diatoms(about 50/50) for another couple weeks then I scraped and rinsed again, I roughed up the screen a little more to see if that would help but now I am growing just diatoms, also have some diatoms on the sand bed. I built based on 3 cubes a day and am lighting it for 16 hours a day.
  2. Turbo

    Turbo Does not really look like Johnny Carson Staff Member Site Owner Multiple Units! Customer

    Another busy weekend, sorry for the delayed reply!

    Some pics would help, post any that you might have taken, or take a few current growth pics

    When you say diatoms, I assume you mean a brown slimy coating? A bit stringy looking maybe?

    One of the things that you mention is re-roughing the screen; it kind of sounds like you didn't wait long enough for the screen to mature, and the re-roughing might have started your screen over to a certain extent.

    A roughed-up plastic canvas screen generally can take 4-6 weeks to mature, but each system is different, and it's hard to write "rules" that everyone should follow, or "expectations" for what everyone should see.

    Let's start with pics and go from there.

    I'm also wondering if you are over-cleaning. For the first month or even 2 months, you should not have to scrape. For the first month, in most cases, all you need to do is swipe your palm across the screen to remove any of the brown slime and detach a good portion of the GHA if there is any, anything left behind should be left as is. At most, rubbing with your fingertips to loosen some thicker growth (or picking at it with thumb & forefinger)

    Overcleaning is the #1 mistake, so let's get that out of the way if that's what is happening
  3. Here's a few picks, When I started the scrubber it was diatoms for the first few weeks then green algae started to grow then I scraped it and rinsed with fresh salt water, it was the same for couple more weeks, mostly green, then it went back to diatoms only so I cleaned it and re roughed it, now just diatoms. I have a microscope and I'm sure it's diatoms, they look like green triangular icicles.



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    Last edited by a moderator: Sep 12, 2016
  4. Turbo

    Turbo Does not really look like Johnny Carson Staff Member Site Owner Multiple Units! Customer

    I don't know how to find BB code in Imgur, only seems that you have to just paste the URL, I fixed your post above (which was one big URL)

    you have to let the diatom/dino phase pass, but you want to keep that stuff off the screen long-term. Meaning, it will tend to inhibit GHA growth but that's only temporary. I think that scraping it well and roughing it up basically got rid of the GHA that had anchored. What I would do is just give it some time. Don't clean it, at all, for a few weeks. You have to let the GHA grab hold, and then "help" it by cleaning off the diatom growth. At the most, you should take it off every 4-5 days and try to get the diatoms to detach via rinsing. In freshwater is fine (tap water). Rubbing it with your fingertips should loosen most of the brown growth off, but those diatoms are sort of "laying the foundation" for the GHA so don't clean too vigorously.
  5. OK Thanks, I will give that a try.

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