Slit flow rate

[malvalv99]

Hi all, just in the middle of building my scrubber following the advice on here and not sure on something.

My feed will be direct from the overflow and just started thinking if the slit would be able to handle the flow??

I can't check for real, I haven't got the tank wet yet, so was wondering if anyone knew what flow it could handle.

I just can't seem to get my head round it being able to do it, if it was direct from a pump and under pressure I could probably understand, but gravity fed?

My slot is 27cm and after head reduction, looking at around 1400lh going back to the sump through the scrubber. Will this be able to cope?

My original design was lit both sides and only used one of the two overflows from the tank. I struggled fitting 2 lights in so have gone the one sided/bigger screen route. To keep the flow up both overflows will have to be used. I don't have a problem putting in a t piece, to direct any excess direct to the sump, but would really want it going through the scrubber.

Any help appreciated, cheers.

[rleahaines]

If you feed a scrubber from the overflow directly - and all the water goes through it first - then the flow rate will be the rate of the pump going to your display. If you use only one overflow then the rate would be roughly what you get on that overflow.

Easy to measure. Just take a liter container and measure how fast it fills from the overflow. Then do the math.

If you build the scrubber with proper materials - PVC piping - a 27 CM long slot with a width of .5CM or so should handle the flow. You can put a ball valve on one end and route some of the water away if necessary and control the flow that way.

[malvalv99]

Thanks for the reply rleahaines. I'm ok figuring the actual flow rate out, I was more worried about if the slit in the pipe could handle it. It's obviously my first scrubber so probably just worrying over nothing lol

I suppose the only way I'm going to find out for real is when I run it. I can see the tank getting wet this weekend :)

I just thought some mathematical genius on here had worked out that, for example, a 1cm slot 4mm wide can handle x amount per hour. Then all you do is multiply by whatever your length is.

Thanks again, I'll let you know how I get on ;)

[rleahaines]

Many people use a series of 1/4" holes in a pipe instead of a slot or a slot about 1/4" wide. This seems to work fine. When I had mine set up I had a ball valve on the end with an overflow piece of PVS so I could control the flow.

If you look at the thread where there are pictures of installed scrubbers you can see what I am talking about.

[malvalv99]

Cheers mate, off to have a look now.

Unrelated, but I've just decided to split the screen in 2 and make a new pipe with 2 separate slots, so one screen can be cleaned while the others still working. Maybe half inch or so between them. Figured it would be better than putting 1 cleaned screen in every week, no spikes.