Sizing opinions needed

[djmatteo]

I recently adopted a scrubber from a friend and adapted it to my tank, I just wanted to check in with my screen size/lighting and take suggestions. I have a good feeling my screen is to big but will get feedback.

My tank is 125g+55g sump.
Scrubber is gravity fed from display tank.

I feed 3-5 pinches of flake food per day
Screen size is 9.5x9.5
Lighting it with 2 26W bulbs (2 sided image only shows one)
3023

I know right now I am under lighting and my screen is to big, but the 23-26W watt sized bulbs are ideal and cost effective. More than that gets to be to expensive.

I would prefer not to change the length of my screen as the box is pretty well built and changing the screen would mean cutting and capping or replacing the the piece of PVC which while not impossible I would just prefer not to. If I cut the screen down does it have to be square? Or could I cut a make a fat "T" if needed, the only reason I ask is because the first inch or so of screen isnt getting good flow anyway.

So, I am open for suggestions or ways to improve to make this work optimally. I am on day 6 using a brand new screen and its all nice and brown already so its starting to work even with the oversized screen and undersized bulbs.

[djmatteo]

I also was wondering if the screen was cut shorter by ~3" 9.5x6 what could be done to reduce the splash going down the bulkheads on the bottom of the box. Would a simple piece of PVC with a 90° elbow be enough to reduce noise/bubbles?


Also what is more important, correct sizing for your screen:light ratio, or feeding enough to feed the screen.

[kerry]

Both light and feeding make a huge difference. For your feeding a small 3*4 screen would probably be more then enough as this would service up to 10 pinches per day. Have you read this: http://algaescrubber.net/forums/showthread.php?1419-New-sizing-guidelines

[djmatteo]

I actually have read that and am familiar with the new guidelines and MUCH smaller screens being used than the previous version.

My problem with using such a small one is I already have this bigger box which was a hand me down, revamping the physical plumbing of the box to accommodate that small of a screen isnt something I am real comfortable doing. When it comes to DIY im not very handy. Also the 5 inches the water will crash to the bottom of my box is a concern for bubbles.

The last little problem is by greatly reducing the screen size since this scrubber is gravity fed is that I will have to cut back the flow going over the screen which will then force more water down the other water pipe again which causes a lot of bubbles in the overflow section on my sump which in turn sends these bubbles airborne and greatly contributes to moisture in my basement =(

So I guess what would be the biggest screen I can run with the lighting I have and still be rather effective?

[kotlec]

You can simply hide part of your screen from light. Dont need to re size physically.

[djmatteo]

I went on a mission to fix this up a bit... heres what I did.

I cut about 1.5" off the bottom of the screen, then I notched a couple spots on the bottom edges of the screen roughly 3"x3" making the screen to look like a fat T.

The box had 3 bulkheads in the bottom, 2 1" and 1 3/4" I put a piece of PVC in two of them (capped the other), with a 90° elbow on each one, made the 1" slightly shorter than the 3/4" and drilled a few holes in the piece of PVC to try to draw water from inside the box instead of all surface water hopefully reducing some of the bubble intake. I also drilled a small hole on the 90° elbow to hopefully vent some air out.

So now what I have is a box about half filled with water, the bottom portion of the T shaped screen is entirely submerged in water between the two pieces of PVC.

My screen size not counting the part in the water is 9.5" x 4" which = 38 sq inches.

Questions:
Now that my box is full of water do I need to move my lights up or will the original position be fine, currently the bulbs are just a hair above the water line, i can only assume all the light below the water line is going to be wasted and not really hit the upper region of the screen.

Would notching the pieces of PVC similar to that in some overflow boxes be more beneficial bubble wise than having most of it come through the piece of PVC

Thanks, I am really noobish with this so I really am appreciative of your patience and advice.

[djmatteo]

3072

2 weeks of growth on new screen

[kerry]

Not bad at all, the next two weeks should be a lot better.

[djmatteo]

Just an update, my modified box design with water in the box had to be changed again. Reason being I was starting to see cyano growth in the box and I didnt want to take any chances with it making its way into my tank.

The inside of the box had a nice amount of GHA growing on pieces of the PVC, and also note worthy the T section of the screen which was submerged in water was growing a BRIGHT green algae. I was due to clean it today but did not, ill post a new pic when I clean it. Currently its got darker green growth on it, still struggling to get nice even growth. I imagine its because of the size of my screen yet, im not forcing it to go 3d as I read in other threads/comments.