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New Algae Scrubber newbie

Discussion in 'General Discussion' started by lovefish77, Apr 17, 2017.

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  1. lovefish77

    lovefish77 Member Trusted Member


    Thanks everyone for this site and I am glad to be here. A couple of months back I upgraded to a 75 gallon reef tank (from a 40 gallon tank). Setup is a bare bottom tank with an open rock scape. I am using a 20 gallon long sump for the skimmer, heaters, return pump…etc. As part of the setup I decided to build an algae scrubber (coz I am tired of changing and playing with gfo and other media). The diy algae scrubber is 6.5” in width and ~ 12” tall lit on both ends using the following light

    Amazon.com : 45W LED Grow Light, UNIFUN New Light Plant Bulbs Plant Growing Bulb for Hydroponic Aquatic Indoor Plants : Patio, Lawn & Garden

    I started out with light on one side and then I upgraded to both sides. Progression was as follows:

    - Started growing brown slime and then turf green algae on top covering like 50% of the screen, then I took it down to clean, note that it took like 5 weeks (more than discussed on forums to reach a screen that is semi covered with algae).

    - Close to cleaning it I measured phosphate (.35) and nitrates was like 20ppm (much higher than I hoped for really :(. I was feeding about 1.5 cubes per day

    - Scrubber is lit ~ 18hours a day. Scrubber is fed by eheim 1000 pump ~ 200 gph (I have about 6” of screen width)

    - On cleaning I roughened it up it was like starting from scratch. It is taking like 2 weeks just to see some green algae spots, but the strange thing is that green algae is showing up on shaded areas. For instance at the slit of the tube I put two flaps to block light and reduce algae growth at that area, and strangely I am starting to see green blobs of algae under those flaps!!!!!. Another area where I am getting some algae blobs is where the light is partially blocked by the trim of the 20 gallon sump.

    I am looking for ideas, I was hoping that algae scrubber would take care of nitrates and phosphates on an ongoing basis but it is a bit disappointing not to see that happen. Is it wishful thinking to depend on algae scrubber alone?

    Any idea welcome here

    Thanks a lot for looking
  2. Turbo

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

    Welcome to the site!

    It sounds like you actually have multiple issue here that are all contributing in one way or another, and some could be "overlapping" conditions. So don't take this all below as negatively critical or anything, it's just the facts as I see them, so I hope it helps. This should be easily rectified with a few adjustments and most importantly, patience

    When you start out a brand new screen that is roughed up, 4-6 weeks it the expected time, on average, that you start to see enough growth to really start performing some filtration (assuming that you roughed it up initially). What happens during that initial break-in period is that there are deposits made (like calcium, etc) on to the canvas that allow the algae to anchor a little better, and this process takes time. So I would not say that 5 weeks is too long, it's actually about right.

    Then, when you re-roughed the screen, you essentially restarted that whole process.

    Size: 12x6 lit on both sides (now) so that's 72 sq in, on the feeding rate sizing guide of 12 sq in / cube / day that's a 6 cube/day scrubber, but you're only feeding 1.5, so you're 4x oversized

    Light: that type of fixture is generally low-intensity LEDs (255 of them at 45W rated = 0.17W per LED) and while historically that form factor of fixture has not performed well, the one you have in particular doesn't look half bad, it's got a good mixture of LEDs in there, but I think it's too big for the tank in general (you simply don't need a screen that large) and if you did have it on a screen that matched the dims (12x12 screen) then it would do OK but would probably be limited overall in what it could turn around and produce in terms of algal growth (i.e. you would de-rate the scrubber based on the fixture)

    Photoperiod: Even though your light is not "ideal", for where you are at, it's probably actually way too much light, so you're getting a "hotspot" or photosaturation in the middle. The growth in the 'darker area' is a direct indication of precisely that. Too much light + not enough algae to adsorb the incident light = zero growth. The growth in the darker areas means those areas are at about the right level of light. If you could dim the fixture, that's what I would do. If not (likely you cannot) then you might try diffusing the light a bit or blocking part of it somehow (use a safe method that won't allow excess heat to cause some kind of damage). You could also adjust the proximity of the light. You could also try reducing the photoperiod (I would go to 12 hours/day max) and and splitting it up into 1-2 hour segments with 15-30 min inbetween segments. Once you get full coverage on the screen, this shouldn't be necessary anymore. But, you are oversized so you will just have to find the right spot.

    With respect to lighting, this is where a picture of your setup really helps a lot. I'm just guessing at what your issues could be without a picture, it's a very important piece of the puzzle.

    Flow: the Eheim compact 1000 is not a good pump for algae scrubbers. I know this from experience, the first round of the Rev 1, I sold this pump with the unit. Initially it has about 195 GPH at 12" vertical plus the slot pipe, seems like it's spot on, right? But add any kind of algae growth in the slot and that flow drops rapidly, after 3-5 months mine was actually flowing at about 70 GPH. I had sold about 30 of these and I replaced them all at no charge with Rio 1100s, which is a much beefier pump and has better head loss curve characteristics.

    I don't recommend Maxi-jets or Cobalt MJs for the same reason - they are not pumps that are meant to provide flow under any kind of backpressure. You have to go to the Rio series pump, or an equivalent.

    So like I said, many possible factors, and I didn't even go into the tank inhabitants or contents, etc, as those are likely not critical at this point. First thing is to focus on the basics. You're on the right track, just don't over-clean & don't clean too frequently - let it break in and do partial cleanings to allow a proper "base" to form.
  3. lovefish77

    lovefish77 Member Trusted Member

    Turbo- thanks for the detailed comments and critique, this is what i am looking for really. few comments:

    Size - i know it is a bit oversized, but one thing i didnt meantion is that the screen is fully lit (all of it) from one side, the other side is not lit for the entire height ( i will try posting a pic coz it is very hard to explain it in words). But i will do my best: the screen is hanging to the side of the 20 long. on one side i have the led fixture covering the whole screen length and width. On the other side the second led (slightly weaker @ 30 watts, not 45W like the other one) sitting on the the lip edge of the 20 long across the width of the tank. So effectively not the entire 72 square inches are lit really. The light is about 1.5-2" from the screen (on both sides) only separated by clear acrylic 11x14" sheet to protect against splashed water from the screen causing a disaster. One thing i am afraid to do is feeding more, i have two tang, 3 anthias, cardinal, 2 clowns... like 9 fish so the tank is heavily stocked. i mean i can always feed more, those fish can eat like pigs no matter how much food you throw in. Just afraid to feed more given high nitrates and phosphate reading i had. One thing i can do is think of some frosting or something to put on the acrylic sheet to diffuse the light somehow. Either that or i will dial the photoperiod down to 12 hours or so).

    Flow: i can get the rio pump you mentioned, i have done one tweak yesterday i have to admit :)
    The sump has no baffles , single compartment, so the pump feeding the scrubber was sitting behind the return pump (as scrubber is at the edge of the tank) so i though maybe no algae is produced coz this area of the sump is stale in terms of water movement. So i placed the eheim close to the filter socks (to bring nutrient rick water to the screen) and used tubing to extend all the one down to the algae scrubber, just a thought!!!

    but can a scrubber suffice in the long term (once dialed in) for nitrates and phosphate removal? that is a deal maker/breaker for me really...

    keep your thoughts coming please, i am here coz i know you are a guru on those scrubbers :)

    thanks again
  4. Turbo

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

    Pics would help - take a few and post when you get a chance :)
  5. lovefish77

    lovefish77 Member Trusted Member

    ok will try n capture some photos soon. But my main question is; if i manage to tweak the light or the scrubber in general, can i feed like 5 cubes a day and still get very low nitrates and phosphates? i am just getting discouraged and seriously thinking to start carbon dosing once my alk goes down to 7 or so. so is the scrubber really worth it if it is tweaked right? or consider other supplementary measures? that is the question buzzing in my head really :)
  6. lovefish77

    lovefish77 Member Trusted Member

    Dont know if you can see the images, they are messed up somehow and flipped over!!!!
  7. lovefish77

    lovefish77 Member Trusted Member

    This is the view from the side, gives you a good idea of the overall setup

    Attached Files:

  8. lovefish77

    lovefish77 Member Trusted Member

    This is the slide view where the entire screen is exposed to light

    Attached Files:

  9. lovefish77

    lovefish77 Member Trusted Member

    This is the view from the other side (semi exposed side of the screen), what you see is the back of the led.

    Attached Files:

  10. trivodi

    trivodi Member

    I think the scrubber is way worth it, If big enough and properly set up you can feed as much as you want. I oversized mine because I had phosphate leeching out of my rocks and now I have to dose nitrate and phosphate to keep corals alive.

    Carbon dosing will eat up your nitarte and leave a bunch of phosphate most likely. I tryed that and wasn't impresed. You are better off with biopelets but even that is not as good as an algae scrubber in my oppinion.

    If phosphate is the problem I would get rid of all sand everywhere or if you have to have sand siphon it weekly, like all of it everywhere. I had sand that i didn't clean and thats how my rocks got loaded with phosphate. Also do 10% water changes 2-3 times a week until your phophate and nitrate goes down, it might take a while.

    Anyhow the scrubber is hands down the best thing I have come by. Its hard to beat the filtering capacity of hair agae, nothoing comes even close to it.

    My advice about your lights would be to get good LEDs like Cree and make your own, do 660 and 410, don't do blue, 410 is a lot better, also hookup the bigest pump you can get, it will make your life a lot easier and if you want it real easy then get one of Turbos Scrubers, they are amazing.

    This is where i got my box (not shure if its ok to post but feel free to remove if not)

    Algae Scrubber ATS Plexi Box

    That box is big enough for a 5-6 cube scrubber, if you need 2 cube just make the screen and the slot smaller.

    Here is my thread about the dosing

    Dosing Phosphate and Nitrate With Algae Scrubber
    Last edited: Apr 17, 2017
  11. lovefish77

    lovefish77 Member Trusted Member

    thanks i run a bare bottom reef tank. I think turbo just told me that my led are strong that is why i am not getting enough growth, so i added a diffuser to see what will happen. Don't think i need stronger led though, thanks anyway :) will keep you posted. My phosphates are high and cant feed high until i see the scrubber accumulating a thick layer of algae.

  12. trivodi

    trivodi Member

    I ran bare bottom too, my rocks took about 6-8 months to unload the phophate with scrubber and water changes, check your nitrate and if its undetectable dose some. Bring it up to 02-0.5 ppm and keep it there, that will speed up the phophate consumption by bacteria and algae. You may not be growing algae because your nitrate is too low.

    If you need to dose nitrate don't use the stump remover, the powder stuff must have something in it thats not reef safe, I had fish die from it, get food grade nano3 from ebay and make your own solution or the brightwell nitrate, i use the brightwell
  13. lovefish77

    lovefish77 Member Trusted Member

    Turbo - any thoughts or questions on setup? dont know if you can make anything out of the pics though
  14. Turbo

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

    I think your lights could be too close. I would back them off about 1" further away

    Bigger is not necessarily better. It's about the rate. If you go much over about 40-50 GPH/in of screen width, you hit diminishing returns and possibly negative returns - that's why I stopped pushing the "high flow" concept, because it doesn't necessarily product results for everyone. Some, yes - but in reality, going with a larger screen produces much better results vs a smaller one with a ton of flow.

    Personally I don't think sand is a problem, sand will build up nutrients/waste but that doesn't directly cause phosphate buildup in rocks

    I haven't researched this but I've read threads from several others that used stump remover and it worked fine, I wonder if it's a specific brand that is considered safe? It's certainly possible that all are not equal.

    5 cubes/day in a 75 is an insane level of feeding - just saying. In my heavily stocked 120 (yellow tang, 4 chromis, 3 clowns, 5 PJ cardinals, 4 anthias, melanarus wrasse, angel, clown goby, etc) I feed maybe 2 cubes/day plus a dash of this & that - Max 3 cubes/day, and that's a lot. The fish you listed will be fine on one cube/day IMO. That's if the tang police don't track you down for keeping 2 in a 75 :p:D:D
  15. lovefish77

    lovefish77 Member Trusted Member

    thanks Turbo, yesterday i added a diffuser for the 2 lights (foam they use to package electronics like pc screens), it is still letting light through but cut the intensity a bit. Will see. I know 5 cubes is a lot, i never fed more than 1.5 and like 7 square inches of nori. the reason honestly why i made the screen bigger is that: when i raised the screen up, i didnt want water to splash down on the sump water surface, so i ended up extending all the way down to the water line, that is all. Will keep an eye on algae and will add
    more diffusion and keep you posted.
  16. Turbo

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

    I would not use that - you are cutting the direct intensity down by 90%. Use diffuser from home depot or lowes, the kind that goes in a ceiling grid system for diffusing a recessed light

    like this, smooth on one side, bumpy on the other, bumpy side goes toward the light source

    Shop OPTIX (Common: 24-in x 48-in; Actual: 22.187-in x 46.437-in) 7.12-sq ft Prism Ceiling Light Panels at Lowes.com
  17. lovefish77

    lovefish77 Member Trusted Member

    ok will keep an eye and see, will give what i have a shot first. lights are still close. Algae is growing inside the flaps at the top and this is SHADED, its not getting any direct light, that is why i though of cutting the light with those diffusers. Will see what happens and keep you posted. Another option is to diffuse using mesh screen 7 used for making the screen, i have an extra one that i did not use. will see
  18. trivodi

    trivodi Member

    The spectracide stum remover that's a powder is the one that's no good, I had fish die from it. I used the one that's granules long ago and it's fine but I don't know if you can get it anymore. I
  19. trivodi

    trivodi Member

    I didn't clean my sand for about 3 years and it was loaded with detritos when I removed it all. I did water changes here and there. After I removed the sand, my rocks about 20 pounds, were full of phophate, over 1 ppm for at least 6 months with regular water changes and gfo

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