New Algae Scrubber newbie

Unlikely that heat has caused the screen to bend. More likely, your slot is not pointing straight down or the slot is not straight and/or even width

 

the streamers are not a result of an improper width slot, unless your slot is narrower than 1/8" to begin with. Streamers result when you have light shining directly on the slot/screen junction, causing algae to grow there. This is why I came up with the light blockers.

Increasing the width of the slot will likely just result in uneven flow since you will increase the "capacity" of flow needed to get even sheeting across the entire screen, and that will only be temporary (until algae fills in again and causes streamers)....so that answer is to block the light from getting to the slot/screen junction

There are several ways to do this, my light blockers are just one of them. You can easily DIY something

 

I would say no. One scrubber enthusiast posted (on this site I believe) that he tested levels before and after cleaning, and went to an extreme and tested every few hours or something over the course of several days, and was able to show that the "spike" in nutrients post-harvest only lasted about 24-48 hours or so.

If you don't vigorously clean, it's possible to have no spike. "cleaning" should be replaced with "harvesting". You don't ever really want to "clean" your screen. You just want to thin it out. Always leave some behind. Sometimes, I leave enough on the screen that other would consider it ready for cleaning. I'll have to post a pic or two from my phone.

 

So this screen is on its last days. Actually it's been on it's last days for about 4 months. As you can see, even a beat up ratty screen can work great. Anyways, before harvest



After harvest

 

You probably shouldn't go over 21 days between cleanings, 16-18 is my max and at that point (with the growth this thick) the algae will all fully detach from the screen, meaning a bit of a slower recovery.

If you don't have a 3D growth chamber, usually you will want to shorten the time between cleanings, but it all depends on your specific scrubber and how much is produced, and what type of algae also. If it's GHA and light is getting to the base, you can let it grow longer. If it's slimy or gooey yellow (which tends to block like more easily) then more frequent cleanings are better, but you still don't want to "clean". Partial removal is one way of removing growth without going back to square one, like an X pattern on one side and # pattern on the other (lets light from one side to the other)

 

Like this

 

If that's ~30 days from a bare/new screen, you will want to at least give it a rub & rinse to loosen up any poorly attached growth. Usually you won't have growth that is sufficient enough to mandate actually scraping the screen for about 2 months. Most of the time, within the first 6 months, you can remove enough growth just by "dragging" a scraping tool (versus "chiseling")

 

Saran wrap will not prevent growth from filling in the slot/screen junction, it just prevents streamers from jetting water away from your scrubber. You need something opaque to actually block light. This can be as simple as a section of a black plastic garbage bag, but I don't trust that, my thought is it can get loose and get into your pump or your pump strainer...that would be bad

If you have an open-ended slot pipe, you can take a larger diameter pipe and cut it so that there is a 1/2" or so gap along the entire length, then just slid that over.

Like this: Simple easy to make light shade.

 

#7 is the correct size mesh.

When you say "bend" what do you mean exactly? Is the part of the screen you insert into the slot slightly longer than the slot itself, such that is causes the screen to bend lengthwise? There should be about 1/8" "wiggle" room for the screen to slide back and forth.

If one side of the screen gets slightly more flow, then the slot might not be pointing straight down. Not a big deal, as long as the growth you are getting is enough to filter for your needs (that is the key to remember)

If you are using zip-ties to hold the screen into the slot/pipe, one thing to be careful of is to not pull them too tightly. You don't need these tight at all really, they only need to keep the screen inserted into the slot. Pulling them too tight can cause the slot to pinch closed, and can result in the problems you describe (excess flow on one end, uneven flow from side to side)

If you are describing flow that is more at one end of the screen compared to the other end, which might present itself as "arcing", that could be uneven slot width, or it could be too much flow. You can have too much flow. The 35 GPH/in guideline is pretty solid from what I have found - there is very little reason to go much past that. Going to 40 or 50 GPH/in can get you a bit more production, but you have to have very good production to begin with in order to crank up the flow. i.e. you have a need to put it into "overdrive" = high production, but still high nutrients. Even going to 25 GPH/in for a new screen is OK as long as the light intensity and flow are somewhat balanced.

Hope that helps, I think you have more than one thing going on here