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Thread: PAR in Scrubber vs Display

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    PAR in Scrubber vs Display

    In the basics thread on RC, srusso brought up the scrubber PAR vs DT PAR. I'm sure he'll jump on here but he is having a bryopsis problem in his system. He increased his DT lighing significantly and now his scrubber is essentially being out-performed by the display tank lighting.

    Regardless of that, it brought up an interesting concept. Is there any type of correlation between how powerful your DT lighting is compared to how powerful your scrubber is? For example, in terms of PAR at the surface (or 1" below the surface) of the DT compared to PAR at the surface of the scrubber substrate?

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    Re: PAR in Scrubber vs Display

    How right you are Bud... here is what I posted on RC, comments welcome.

    FIRST POST

    On a side note, I have reason to believe I may have discovered a new "rule".

    Scrubber PAR should be equal or greater than that of your display lighting.

    At least this is the case for me... allow me to explain...

    Some of you may or may not know my tank has become infested with bryopsis... Its bad... like a... really bad.

    About 4 months ago I purchased all new lighting. Went with top of the line metal halide equipment. The change in PAR was from a crappy (ebay) 250 PAR at the water surface to now 1500 PAR... (anyone see the problem, my lighting is NOW like 4 feet from the top of the tank...)

    now my scrubber didn't get an upgrade... it is still using the crap drop lights and 23w CFLs. AND if you have been keeping up with the reading the PAR reading from my scrubber are about 200 - 300...

    With the scrubber being on for 18 hours a day and my tank lighting about 12 -10 hours, (I like to see my tank on early during weekends) the tank was receiving a TON more PAR then my scrubber.

    So I believe I flipped the algae filtering from a sump scrubber to an entire system turned into a scrubber. Needs less to say the output of the scrubber declined over the four months, as the bryopsis did its thing and took over everything. I felt I had failed and a weed had won the battle.

    Equipped with a new outlook, I will attempt to fix my own ongoing experiment of a reef tank.

    Ps... yes I tried the kent magnesium thing... I am going to try and get the balance of power corrected, now that I may have found my issue.

    I think the main take away here is, scrubbers need lots of quality light.


    SECOND POST


    I am still trying to figure out display tank lighting myself to be honest. My first attempt an ebay "250w MH w/ 4 39w T5 actinics"... the T5's had no cooling so it killed brand new bulbs in short course, and the MH ballast was some crap hardware store deal. This unit was designed with legs and sat on the rim of the tank, 6" above the water surface. Thats (4*39)+250 = 406 watts of power and nothing to show for it!

    My reef club loaned me a PAR meter to test, was only getting 250 to ~300 PAR at the water surface! (scrubber was working wonderfully during this time) While I had the meter I tested the scrubber, and got 250 to ~300 PAR from my CFLs with aluminum foil reflectors...

    SO, a good friend gave me a great deal on some brand new equipment he had to off load, due too a failed tank upgrade project. I now have a Lumatek 400W Multi-Wattage (250W, 400W) Ballast. A Radium 250w mogul based 20K MH, and a CoralVue reflector (looks like mirror inside). Hung it 8" away from the surface and PAR tested... 2500! Moved it to 13" from the water surface... 1500 PAR! (At this point my wife is getting ****ed b/c the "fish tank light" is now lighting the room more than the tank)

    Left it at 13", it was all I could manage cut the time back in effort not to shock the corals. I am not going to lie, I was rather proud of my 1500 PAR... I'd say once I reached about 6 hours a day thats when I started noticing some algae growth in the tank.

    If you do some shoty math...

    Display - 1,500PAR x 6 Hours = 9,000PAR a day
    scrubber - 400PAR x 18hours = 7,200PAR a day

    To make thing worse the schedule got to its normal 10 hours a day and about 12 hours a day on the weekends....

    By this time the scrubber was nearly producing nothing, I had started dosing kalk, still feeding the same crazy amount of food I had always been feeding when the scrubber was working normally... and for the last two months been heart broken and ready to give up...

    That brings us to about three weeks ago, Bryopsis had choked out my zoas, had grown its roots into some SPS. Monti's seem fight it off well, and its covered my claim, it still opens fine though... I turned off the tank lights now for almost two weeks now. My scrubber growth was dark green/brown this week... cleaning it now every 4-5 days.

    Even though the light is off, I raised it to the top of my ceiling, about 3ft... lol

    I went from grossly inefficient lighting to extremely efficient, well actually too efficient... Like Yankee stadium in my living room if the light is on... Either this light now has to be replaced, or the tank goes to the basement...

    In the mean time I plan to frag what is still left alive, setting up a QT for the corals while I figure out my lighting issues yet again...



    NEXT POST


    In summery, I believe a scrubber requires more or equal PAR for your scrubber than the PAR reading of the water surface of your display

    That may seem crazy but...

    Your display is X deep. The layer of water flowing over your scrubber is very thin... And you can put the lights as close to the scrubber as needed.

    So you need good lighting for both your scrubber and your display, but the scrubber PAR requirements are far easier to achieve.

    The formula may be

    Display PAR x display Hours = or < scrubber PAR x scrubber hours.

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    Re: PAR in Scrubber vs Display

    Wow very onteresting. Id recommend getting a smqller light.. why waste all that energy lighting up your living room..

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    Re: PAR in Scrubber vs Display

    I remember SM saying that algae turf is not growing under water well. If this is still true , equation is not right sign to put among DT light and ATS light as other parameters has to be considered. What proportion DT/ATS - that is right quaestion imho. Plus algae gets burned at high lights.

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    Re: PAR in Scrubber vs Display

    Quote Originally Posted by RkyRickstr
    Wow very onteresting. Id recommend getting a smqller light.. why waste all that energy lighting up your living room..
    Agreed... just very painful to yet again explain to the other half that this "new" light is still not what I needed.
    On the bright side, that light I got this time is actually something someone else may want to buy... unlike my previous ebay purchase...

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    Re: PAR in Scrubber vs Display

    Quote Originally Posted by kotlec
    I remember SM saying that algae turf is not growing under water well. If this is still true , equation is not right sign to put among DT light and ATS light as other parameters has to be considered. What proportion DT/ATS - that is right quaestion imho. Plus algae gets burned at high lights.
    Right... the algae that is growing under water very well is not turf, its bryopsis... Algae will burn if the lighting is too intense yet, only relative to the duration of photo period.

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    Re: PAR in Scrubber vs Display

    You might think about going LED on your scrubber. I get much stronger growth with them than I got with 5x more watts of T5. I had bryopsis in an old tank and could never out compete it with a T5 based scrubber. Tech M would kill it, but it would come back. I finally just tossed anything that had bryopsis on it when I upgraded tanks. I wonder if an LED scrubber might be strong enough though.

    Sent from my DROID2 using Tapatalk

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    Re: PAR in Scrubber vs Display

    I think your putting too much into a PAR #. PAR is not as simple as putting the sensor x inches from a light and reading the # on the screen, spectrum plays a much bigger role in what that # really means. Also, I am sure 1500 PAR is a few inches directly below the light source, what is the PAR throughout the tank? Due to how much PAR changes every inch you move you can't just add/multiply numbers. The best you could do is take as many different readings in different locations and then get an average #.

    Since my tanks are LEDs now and use controllers I have a gradual ramp up and down of the lights to mimic the readings I got from a friends tank that has SolaTubes over them. PAR readings were taken June 21st (longest day of the year) with the sensor on the top tank brace about 24" below the tubes. My meter has a log mode and it takes a reading every 30 minutes and records it. Just to give you an idea of what is more "natural" in terms of daily sunlight/PAR.


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    Re: PAR in Scrubber vs Display

    It just comes down to how strong the scrubber is. PAR, 2-sided, rough screen, 3D, cleaning half, all play a part. Any one can make a scrubber twice or half as strong.

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    Re: PAR in Scrubber vs Display

    Quote Originally Posted by MorganAtlanta
    You might think about going LED on your scrubber. I get much stronger growth with them than I got with 5x more watts of T5. I had bryopsis in an old tank and could never out compete it with a T5 based scrubber. Tech M would kill it, but it would come back. I finally just tossed anything that had bryopsis on it when I upgraded tanks. I wonder if an LED scrubber might be strong enough though.

    Sent from my DROID2 using Tapatalk
    I had the same findings with tech M, although I wouldn't say it killed it...
    LED is in the plan but far from being able to get the funds together for it.

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