Reasoning against dual screen builds?

[Bilk]

1-sided has half the filtering of 2-sided, even with the same wattage, because with 1-sided the roots die twice as fast from darkness.

I actually don 't see the difference between incorporating two screens back to back in one unit vs THIS

This part, in particular, applies to the discussion:

The number of gallons or liters of water does not matter. If you feed more than this, you can get multiple units; multiple units are preferred because you can clean one per week, and because you'll always have one filtering while the other starts growing again after a cleaning.

* emphasis added by me

So here we have a single sided unit and you suggest that people should purchase multiple units for the same reason the OP suggested and I suggested (in another thread), to keep scrubbing action working in the system after one screen is cleaned so the bioload absorption doesn't fluctuate too much.

So which is it?

[SantaMonica]

I guess there's some light that goes thru and then reflects back again from the reflector on the opposite side

That's the definition of a 2-sided screen: Light and flow goes through it.

but that's only until the algae starts to fill the screen.

That's all the time it takes for the roots to die.

[Floyd R Turbo]

There is no difference. Like I said, you can do what you suggested, having back-to-back screens, alternating cleaning, or you can get 2 single sided HOGs and alternate. It makes no difference in those 2 scenarios, because in both examples, they are single sided. The only difficulty becomes placing a light source in between the 2 screens and protecting it. This is more difficult to perform as a UAS as you can imagine.

I was saying the difference would be if you ran a double-sided scrubber of the same size (same LxW as one of the single screens), which had 2 screen sections (but in half vertically), and you alternated cleaning those. Because it's double-sided, it is inherently better, no matter if it's UAS or waterfall, with half of the total LxW.

The difference between a dual-single-sided screen scrubber and a single double-sided screen scrubber is that in order to "equal" the scrubbing power, you need 2 single sided screens, each one of them being the same size as the double-sided screen. Because you need the same physical growth area - if your single sided screen was 4x6, then you have 24 sq in of growth area. Your double-sided screen has 24 sq in of growth area on each side. I say "equal" because as discussed, single sided screens are less than half as powerful as a double sided screen when both are properly sized (i.e. the single sided screen is twice the LxW of the double sided one, with the same amount of light, all on one side)

[realtime3d]

I wasn't trying to start a war as I've been following SM, Floyd and others' posts over the past year. I was only hoping to kindle some discussion. As I think I stated earlier, my goal was to reclaim some lost surface area because of the 3/4" drain pipe eating into my 5" vertical clearance. Either way, I thought I'd throw up some photos of the build that's still a WIP. They've been running about 2 weeks with one screen being cleaned a week ago. I get decent growth for its age but need to diffuse some of the LED light because of close proximity to the screen itself. You can also see the bubbles on the left side from the Durso I mentioned in Rygh's Gen4 build thread. Comments and suggestions welcome! Thanks again for everything this site's contributed to scrubber evolution.

[Bilk]

War? Hope my comments and questions weren't taken that way. It's just a discussion of what practices work and how they may be improved or why certain things don't. I find there's a lot of information to be gathered here. I'm really looking forward to utilizing an ATS on my system.

[Bilk]

Just to add, I may order some specular mylar to include in my build as the leds I have do not have reflectors. They have a built in heat sink though and don't require additional cooling. It's why I chose them. Don't want more fans (more noise) added to things. These leds are used for signage to replace neon or in lieu of neon. I may need to add some blues though. They have multi-color pucks and might be a good option as well. I think they'll work just fine.

[Floyd R Turbo]

I didn't mean it to sound like a war either - just trying to disseminate information, sometimes it does tend to sound a bit heated.

mylar may or may not help with LEDs, since they are directional. These signage LEDs are likely still directional also, if they are the ones I am thinking of (the little squares with 4 LEDs?) so you probably don't need any reflectors. 90% of the light is thrown forward in a cone, the only light you see from the side is really negligible. LED intensity is much higher, so there is much less need to gather the small percentage of stray light and direct it forward. However if you place the array far away, a cone or tube of mylar might help. But for the really low power LEDs, you want those pretty much right against the screen (for <1W LEDs) and tightly packed so this is not an issue.