Intro' and thoughts on this simple design

[Rumpy Pumpy]

Hi, I am Bill from the UK.

I've been looking for a way to reduce NO3 in my FW 55 gal tank for a while. I built a coil denitrator a couple of months ago but it was not very successful (I suspect it was leaking oxygen in somewhere).

Having been following this forum for a while I decided to have a go at building a simple scrubber.

One of my problems is that I have very limited room under the tank to accommodate, I have a sump, the design of which is not ideal, and there is not much headroom above it.

Anyhow, yesterday I cobbled together a simple canvas screen, suspended over the sump by hooks in the underside of the cabinet at one end and sucker clips inside the sump at the other (easy to remove for cleaning), water flow provided by a 12v powerhead and light by a single CFL bulb.

Here is a quick video of it in operation. It's been running for less that 24 hours so there is no growth so far.

http://www.youtube.com/watch?v=LXIFbTGBB5A&e

I think I'm going to have to incorporate a sprinkler bar to spread the flow of water over more of the width of the canvas and some better lighting (thinking of getting a couple of flexible necked LED desk lamps for that)

Anyhow, all thoughts and suggestions would be welcome.

[worley]

Hi Bill, nice to have another fellow Brit on the boards!
Is that the entire flow of water you have available? If not, higher flow would be good, as well as spreading it out more evenly across the screen.
I don't think the flexible LED lights will be anywhere near enough, so if you want more light, add a second CFL bulb, and/or move the other closer (watch that it doesn't get splashed of course, and don't forget RCD circuit breakers on all the fish tank equipment!).
Tom

[Rumpy Pumpy]

Thanks for the reply.

That is all the flow I currently have, but I reckon it will pass the entire volume of the water at least once an hour (my sump return pump turns it 15 or so times an hour). I suppose i could get a bigger powerhead or plumb the thing directly into my weir outlet somehow.

The LED lights I had in mind were the 240v spot types like this one

http://www.besthomeledlighting.com/files/1674216/uploaded/PAR20_1.jpg

...used in a goose necked desk lamp so they could be placed very close to the canvas.

Would a couple of those be adequate?

[worley]

What (W)attage are the LED bulbs and can you find out the Lumens output too?
I would think you would need loads of those bulbs.
As for the flow, you need 35 Us gal/hour per inch of width on your screen, so if it's 12" wide, you want 420 us gal/hour or 1600l/hour to flow evenly across the entire screen
But as yours appears to be single sided you can half those values, so 210 us gal/hour or 800l/hour should do it. As it's single sided though, you need twice the area (and lighting) of a double sided screen lit from both sides

[Rumpy Pumpy]

What (W)attage are the LED bulbs and can you find out the Lumens output too?
I would think you would need loads of those bulbs.

Dunno. I saw some working last night and they were less than impressive frankly. Back to the drawing board light-wise.



As for the flow, you need 35 Us gal/hour per inch of width on your screen, so if it's 12" wide, you want 420 us gal/hour or 1600l/hour to flow evenly across the entire screen
But as yours appears to be single sided you can half those values, so 210 us gal/hour or 800l/hour should do it. As it's single sided though, you need twice the area (and lighting) of a double sided screen lit from both sides


It's currently delivering 1 litre every 13 seconds, about 280 litres per hour.

So I guess I'll be needing some more flow.

[worley]

You'll need four times that flow then, and as evenly as you can get.
At the moment compact fluorescent bulbs are by far the cheapest light output to power ratio in the short to medium term, as you'll need to replace the bulbs every 3-6 months they get a bit more costly, but I would think after 2+ years LEDs would be more cost effective in terms of not having to replace them and the fact that the newest ones are more energy efficient (light output per watt, and in terms of colour specturm) than compact fluorescent bulbs. I have still to dable in LED lights on my scrubber, but from the experiences I've seen on the forums here, you'd needs LOTS of very high powered LEDs and it's difficult to get the right mix of colours, distance etc so the colours merge etc.

[SantaMonica]

Flow is the main problem here. Get a bigger pump first, and put it in the sump.

But actually, I'm not sure I'd pursue a slanted screen at all. You are going to be tinkering and fixing and adjusting things for months, all while you are not getting any filtering. Really, I would just build a scrubber in a fashion that is known to work. And in your case, it would be a 2-sided screen of about 50 square inches, inserted into the water pipe, fed by a larger pump, and with at least a 23W CFL 2700K Floodlight on each side. This will give you the most filtering with the smallest size, and will be working in about a week.

[Rumpy Pumpy]

Flow is the main problem here. Get a bigger pump first, and put it in the sump.

But actually, I'm not sure I'd pursue a slanted screen at all. You are going to be tinkering and fixing and adjusting things for months, all while you are not getting any filtering. Really, I would just build a scrubber in a fashion that is known to work. And in your case, it would be a 2-sided screen of about 50 square inches, inserted into the water pipe, fed by a larger pump, and with at least a 23W CFL 2700K Floodlight on each side. This will give you the most filtering with the smallest size, and will be working in about a week.



Thanks for that. I was coming to a similar conclusion myself.

My problem though is lack of height.

I'm currently considering upgrading to a much larger tank, (probably a 6 x 2 x 2) which would have a lot more space underneath to construct a much bigger, more professional scrubber.

In the meantime, I might just let this one run as it is, purely as an experiment.

[worley]

I'm currently considering upgrading to a much larger tank, (probably a 6 x 2 x 2) which would have a lot more space underneath to construct a much bigger, more professional scrubber.

Exactly what I just did, got a 6x2x2 about 2 months ago with a 36"x22"x15" (15" high) sump, but haven't had the time to get the scrubber completed, so it's running on the old one for the moment.
Hopefully I should get it finished this week/weekend.

[SantaMonica]

Why don't you get the acrylic scrubber that greg is selling:

viewtopic.php?f=2&t=163&p=1141&hilit=sale#p1141 (http://www.algaescrubber.net/forums/viewtopic.php?f=2&t=163&p=1141&hilit=sale#p1141)

...it's exactly like mine, only 6.5 inches tall.

[Rumpy Pumpy]

Why don't you get the acrylic scrubber that greg is selling:

viewtopic.php?f=2&t=163&p=1141&hilit=sale#p1141 (http://www.algaescrubber.net/forums/viewtopic.php?f=2&t=163&p=1141&hilit=sale#p1141)

...it's exactly like mine, only 6.5 inches tall.


Cheers for that. I'm PM'd him about shipping to the UK.

[Rumpy Pumpy]

Update:

My experimental scrubber is showing a little growth after 5 days

http://img.villagephotos.com/p/2009-3/1337617/PIC_0039.JPG

http://img.villagephotos.com/p/2009-3/1337617/PIC_0040.JPG

http://img.villagephotos.com/p/2009-3/1337617/PIC_0041.JPG

[worley]

Considering the lack of flow and lighting, that's quite encouraging

[Rumpy Pumpy]

Considering the lack of flow and lighting, that's quite encouraging

Yes, I hadn't looked at it for a couple of days and was quite surprised.

I'm not expecting it to do much filtering though.

I'm going away for a week on Sunday and will leave it running and see how it looks when I get back.

[worley]

I would suggest you clean one half of the screen before then

[Rumpy Pumpy]

UPDATE

I didn't clean any of the canvas before I went away as suggested. I would have done, but didn't read the above before I left.

Anyhow, this is what it looked like yesterday (it had been running for about 2 weeks at this point)

http://img.villagephotos.com/p/2009-3/1337617/PIC_0001.JPG


I took the canvas down to clean it and it looked like this, obviously the growth is much more where the flow of water was at it's highest. Note though that the bottom inch or two on the left hand side of the canvas has growth all along it's width. This part was submerged in the water.

http://img.villagephotos.com/p/2009-3/1337617/PIC_0003.JPG


A good scraping yielded this small handful of algae

http://img.villagephotos.com/p/2009-3/1337617/PIC_0006.JPG


I've reassembled it now and it looks like this

http://img.villagephotos.com/p/2009-3/1337617/PIC_0005.JPG


Nitrates are a bit lower (can't give you any numbers as I lost the colour chart for the test kit. Doh!)

Going forward, I have an idea to construct v.2 from a large roasting tin

http://img.villagephotos.com/p/2009-3/1337617/PIC_0007.JPG

which would sit on top of the sump with the canvas suspended by the grill and water trickled into the centre from above and allowed to run off around the sides. It would also have additional lighting.

Obviously a hole or holes would have to be drilled to allow the water to run into the sump.


Thoughts?

[SantaMonica]

Not bad growth. May work decently.

The grill is metal... you probably don't want SW on that.

[Rumpy Pumpy]

Not bad growth. May work decently.

The grill is metal... you probably don't want SW on that.


Fair comment.

It's actually FW but still...

I'm sure it won't be too difficult to rig up some kind of plastic alternative support.

[Rumpy Pumpy]

A slightly different approach.

Ditched the roasting tray idea for the moment and have gone for this

http://www.youtube.com/watch?v=z7lLTcOC8Vo


As you can see the canvas is now stretched across and slightly submerged inside the sump with water passing over (and under) it. The sump throughput is approx 6000-7000 litres per hour (just put a new pump in today) and I reckon a good proportion of that is passing over the canvas.

The light is still too little and will be upgraded shortly.

I think I may need to make the canvas more rigid and perhaps install a piece of perspex between the water and the light


Views?

[worley]

Get it closer to the surface of the water if you can, also, more light =).
Ok so maybe I'm going overkill with my 240W of fluroescent lights!

[SantaMonica]

Yes it needs to be at the surface of the water, preferably slightly above, so that water falls off the edges. You could make it floating.

[kcress]

Ok so maybe I'm going overkill with my 240W of fluorescent lights!

Well you'll certainly be overkilling your electric bill!! :lol:

[Rumpy Pumpy]

How's this for a light source

http://img.villagephotos.com/p/2009-3/1337617/biglight.JPG


Now I just have to figure out how to fit it

[kcress]

That looks really good for a light!
Tell us more. Where'd you get it?

[Rumpy Pumpy]

That looks really good for a light!
Tell us more. Where'd you get it?


It came from "Wickes" (in the UK)

It's their own brand "42 Watt Energy Saver Floodlight"

Not cheap at £34, but it's a waterproofed unit, should be reasonably economical to run and the bulbs are available on ebay for not a lot of money (http://cgi.ebay.co.uk/PHILIPS-MASTER-PL-T-840-4P-BULBS-42-WATT-NEW_W0QQitemZ200319603641QQcmdZViewItemQQptZUK_Lig ht_Bulbs?hash=item200319603641&_trksid=p3286.c0.m14&_trkparms=72:1683|66:2|65:12|39:1|240:1318)

[worley]

Ohhh I may pop down to my local store, shame I'd need 3-4 of those though.

[Rumpy Pumpy]

Installed, sort of, temporarily, well, it can't fall in the water anyway....hopefully :roll:

http://img.villagephotos.com/p/2009-3/1337617/light.JPG

When I have more space/time I'll use it to build a more professional one.

I thought it would be brighter than this

[Rumpy Pumpy]

I had the other little bulb on 24/7 but I understand from these forums that it is better to have on for 16 and off for 8.

Is it better to have a straight 16-8 or would 8-4-8-4 or even 2-1-2-1-2-1-2-1 be better?

[worley]

Installed, sort of, temporarily, well, it can't fall in the water anyway....hopefully :roll:
:lol:


When I have more space/time I'll use it to build a more professional one.
The basic idea is sound, as long as you have enough light and flow and it's close enough to the water (I think you still need to get it a bit higher), then it should work.


I thought it would be brighter than this
What, the photo or the light itself? Also what colour temp is it? Is it a standard 3500k? The higher colour temps, like the daylight 6500k+ bulbs tend to appear brighter than the same wattage of lower/standard colour temp bulbs, but the lower ones tend to actually grow algae faster

[worley]

16-8 is better, I don't think people have tested it in other ways like those combinations, but I'd theorize that the algae prefers more natural cycles/enviroments for optimal growth, hence why they don't grow when the lights are on 24x7

[Rumpy Pumpy]

I thought it would be brighter than this
What, the photo or the light itself? Also what colour temp is it? Is it a standard 3500k? The higher colour temps, like the daylight 6500k+ bulbs tend to appear brighter than the same wattage of lower/standard colour temp bulbs, but the lower ones tend to actually grow algae faster


The bulb is a Philips Master PL-T 4P 42 Watt/840

The box says 3200 lumens and the colour rendering index thingy printed on it is pointing at the yellow which I think means akin to daylight, not sure about that though.

[Rumpy Pumpy]

16-8 is better, I don't think people have tested it in other ways like those combinations, but I'd theorize that the algae prefers more natural cycles/enviroments for optimal growth, hence why they don't grow when the lights are on 24x7


16-8 it is then.

Makes sense to do it as naturally as possible I suppose.

[worley]

yellow probably means 3500k, which is fine, it would appear slightly less bright than a daylight (they look more white) bulb at the same wattage

[Rumpy Pumpy]

yellow probably means 3500k, which is fine, it would appear slightly less bright than a daylight (they look more white) bulb at the same wattage

Right, I shall look forward to a good crop of green goo then :D

[SantaMonica]

That bulb is a great idea... water proof. High power too, plenty for you. The lower the K, the better (yellow-ish).

You you just have to get the screen up to the surface.

[Rumpy Pumpy]

You you just have to get the screen up to the surface.


How about a swimming float or a piece of flat polystyrene with the canvas wrapped around it?

Would there be issues with toxicity?

[SantaMonica]

Just use a small piece of styrofoam on each corner.

[worley]

I don't think polystyrene is toxic, I've seen people use it to float frags of sensitive hard corals when shipping, works a treat to keep them in the water (upside down)

[Rumpy Pumpy]

Further update

Took it out for cleaning today & this is what I found

http://img.villagephotos.com/p/2009-3/1337617/no1.JPG

After cleaning it looked like this

http://img.villagephotos.com/p/2009-3/1337617/no3.JPG

I've further adapted the design by stretching the canvas over a piece of pond filter grid to make it more rigid and easier to keep in place and bring more to the surface.

http://img.villagephotos.com/p/2009-3/1337617/no4.JPG

Like so

http://img.villagephotos.com/p/2009-3/1337617/no5.JPG

and then mounting it the sump by means of suckers as before.

Here's a quick (but not very good) vid of how it is running now.

http://www.youtube.com/watch?v=eAFVDzzsvyM


I'll run this for a while and see how it goes but I suspect I'll have to bring it right out of the water and run some flow over it in the air.

Thoughts?

[SantaMonica]

Yep you have got to get it up at the surface. And really try to get waves going across it. You might try putting another pump in there, which just agitates the surface.

[Rumpy Pumpy]

Cleaned it again this morning, no photo as the camera's gone walkies (bloody kids!)

It had a good amount of green hair algae and much less of the black/brown slimy stuck this time.

I cleaned it as usual but should I have left some or all of it, given that it' was becoming green?

[SantaMonica]

You want to leave a layer of algae on it, so it does not have to grow back from scratch.

[Rumpy Pumpy]

Not done an update for a while so;

No changes to the set up, i know it ain't perfect but I've not had the time.

But the hair algae is coming along well I think.

It has been cleaned every weekend and this is what it looked like today

http://img.villagephotos.com/p/2009-5/1340429/PIC_0018.JPG

http://img.villagephotos.com/p/2009-5/1340429/PIC_0019.JPG

Last Sunday some of the hair algae was 2 inches long.

Quite encouraging I thought.

[SantaMonica]

Good to see it progressing. Try not to let the HA get more than an inch long, even if it's just a few days.

[Rumpy Pumpy]

Todays cleaning

Before

http://img.villagephotos.com/p/2009-5/1340429/PIC_0020.JPG

After

http://img.villagephotos.com/p/2009-5/1340429/PIC_0021.JPG

Muck left in the sink

http://img.villagephotos.com/p/2009-5/1340429/PIC_0022.JPG

[worley]

Hey, that's looking better!
Have you had any noticeable changes in the tank yet (measured or otherwise)?

[Rumpy Pumpy]

Hey, that's looking better!
Have you had any noticeable changes in the tank yet (measured or otherwise)?


Yes, the nitrates are definitely lower, although still high.

There is no hair algae in the tank now (there was a little before) and much less algae generally, I don't have to clean the glass as often now and it's easier to clean with none of that hard rough algae on the glass that you have to scrub or scrape off.

I did a 50% water change too yesterday (the first for ages), it made little difference to the NO3 reading but then the water comes out of the tap with 40ppm around these parts anyway.

[worley]

EEEEK!!! don't use tapwater for water changes, especially ones that large, use RO/DI water, RO units are dirt cheap, see: http://www.ro-man.com/

[Rumpy Pumpy]

EEEEK!!! don't use tapwater for water changes, especially ones that large, use RO/DI water, RO units are dirt cheap, see: http://www.ro-man.com/

I know, I know... but it's not a marine tank, and I use lots of tap water conditioner, and I've been doing this for a couple of decades now and never lost a fish after a water change (and I used to do a lot more of em), so I think it'll be alright.

Probably.

[worley]

Oh yeah, I keep forgetting that's a FW tank :lol:
I'm actually using the waste water from my RO/DI unit that I use for fresh water top-offs for my marine tank, the waste water ends up considerably cleaner than the tap water. If the 'trates are still high, you could do a bunch of water changes to get them under control then let the scrubber do the rest

[Rumpy Pumpy]

If the 'trates are still high, you could do a bunch of water changes to get them under control then let the scrubber do the rest


Tried that before. It works to a point but, as I say, the tap water around these parts has around 40ppm NO3 so water changes are never going to bring it down below that.

I used to use live plants to keep the nitrates down, which worked to a point, but I now have a number of metynnis argenteus which leave less vegetation than a plague of locusts.

[worley]

If they're at 40ppm, that's not really high for a FW tank, and the scrubber will get those close to 0 after a few months if it's the right size/flow/lighting etc.