Nice build. Will be following.
Nice build. Will be following.
Holy crap. A good surprise for once!
Um I think its working....
Nitrates measure 0.25ppm (Red Sea Nitrate Pro test)
Phosphates measure 0.00 ppm (Hanna Checker 713)
This is AFTER my skimmer overflowed and dumped a 3/4 full cup of skimmate into the tank. I knocked the venturi tube off when I was hanging this bugger (dumb).
All I can say is WOW.
Great to hear it is working!
You will probably never see a difference in growth between the two. The screen is partially transparent, so will
equal out a bit.
I do wonder about that 16,400 lumen spec though.
The white ones that produce the most visible lumens are only 111 lumen/W, so a 90W fixture has to be less than 10,000 lumens.
And on one that looks so purple, I would have thought it would be in the 7,000 range or so.
Hard to tell from picture, but it still looks like it could use more flow.
Have you measured actual flow? Don't trust pump specs.
I don't have any way to measure flow. Aren't flow meters like $175? The QO 4000 was spraying water everywhere so I put a QO 3000 on and it seems to be good. Maybe my screen slit needs to be wider? I did clean the pipe inside and out and also cleaned the pump last night. Maybe that will help.
Updated growth photos, day 46 (week 6.5).
I got 2.8 ounces (squeezed) of algae off both sides. Some was black/dark brown/dark red gooey at the top and the rest was a good darker green color.
90W side
100W side
Here's how I suggest you do it, excerpt from the "basics" thread
For a drain fed scrubber, fill a pitcher with the water entering the sump. You will probably need to rig up a temporary pipe or routing configuration so that you can fill the container. For a pump-fed scrubber, set up the pump in a sink filled with water to the same level as your pump will be submerged, and connect the tubing required to reach the height of the connection to the horizontal slot tube, so that you mimic as best as possible the actual conditions. Backpressure created by the slot/screen is negligible unless your flow rate significantly exceeds 35 GPH per inch of slot length.
Now that you've done all this, fill the container and record the time it takes to fill it. Do this at least a dozen times. The way I do this is by using a recording device, like a digital voice recorder, and just calling out "Go" and "Stop", then afterward, playing it back and using a stopwatch to get the time intervals. You could also have someone else run the stopwatch and write down the times. Average out the times and then figure out how many gallons per hour of flow you are actually getting. If you have multiple drains, measure and extrapolate GPH for each individually, and then add together.
For instance, if you are using a 1/2 gallon pitcher, and it takes 4.5 seconds to fill it, then you would have (0.5 gallons / 4.5 seconds) x (3600 seconds / 1 hour) which would be 400 GPH.
Well heck that is simple enough. I'll give that a try. Thanks!
Ok my flow is approx 515 GPH. My screen is 16.25" wide, so my target is 569 GPH. Is that close enough or should I put back the QO 4000?
Should be close enough. I ran mine for 6 months with 20 GPH/in due to a calculation error. Hence why I stress that in my summary. Currently I run a 20" wide screen on a top-of-tank setup (temporary tank) driven directly be a Mag5 on a 1" line so I know I'm not getting proper flow (haven't measured it, but just based on pump specs), but growth is fantastic.
I was asking because your growth looks very dark but tank is low nutrients. Must be pulling a lot out, or still ramping up. Either that, or it's still maturing. You should have more stringy fluffy green I would think. Maybe the lights are overpowered too, you can see the hotspots on both sides of the screen right where the round light is aiming.
From e-mailing with Sean, he's telling me that LEDs have roughly 2x the efficiency of T5HO, photosynthetically speaking. So watt-for-watt you want about 1/2 of what you would normally use. So for your screen, 15 x 16.25 = 240 ish, you would really only need 120W of LED in the proper spectrum. You're running 190, but 2 different types of mixtures, so I don't know how that affects everything. You would probably be safe backing the lights off of the screen a bit and spreading out the signature, or leaving them where they are and gluing on a sheet of diamond diffuser to your splash guards.
Just thinking out loud. I'm very curious to see how these fixtures work out.
This experiment has been interesting. I do have high nutrients for sure. The screen seems to be getting better and better. I'm just on week 6.5 so about halfway to an "established" screen from what I understand. Adding iron helped a lot. I'm in the midst of adjusting Alk, Cal and Mag back to proper levels. Before I started this little experiement my tank was a mess, with the skimmer overflowing constantly (reversible pump impeller), way too many fish, a blocked overflow, blah blah. My last nitrate and phosphate readings are encouraging.
From what I read, it was low nutrients, N in single digits and P below 0.10. That led me to think that it was high in the past and you're pulling stuff out of the rocks.
I would think that at 6 weeks your screen is pretty well established, w/r to it's ability to hang on to algae growth that is. The 'curing' time is really only related to how long it takes for the base mat of the algae to 'bond' to the screen material. That seems to take 4-6 weeks. After that, you have a much lower risk of algae detaching.
So what was the N and P before the scrubber was fired up?
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