Thoughts on this?

[Rumpy Pumpy]

Here's my prototype in hood horizontal (sorry SM) trough style scrubber

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

It is 35 inches long and 5 and 3/4 inches wide (internal) making just over 200 sq inches of available screen area (for a 200 litre tank). The whole thing lifts out easily for cleaning.

As you can see the water comes in at one end straight from the sump return pump, trickles along the trough and discharges into the tank at the other end.

In the film I have the pump running at half capacity which is giving a flow of just over 260 (US) gallons per hour (45 gallons per hour per inch of screen width). This can be doubled if necessary (but would get a bit noisy)

I am going to use the reverse side of some floor tiles, cut to fit the trough, as a screen. They are nice and rough and have a rippled pattern on them. If necessary I will stick some roughed up plastic canvas on top of those too.

For lighting I'm proposing to use 2 x 38w 4 ft T8 florescent tubes which will sit on top of the trough, 2 or three inches above the screen with reflectors sitting on top. There will also be a 2 x 39w 3 ft T5 unit located under the hood to light the tank which may provide a little extra light to the scrubber.

I realise that this unit is not going to be as efficient as a vertical scrubber but it suits my tank/cabinet arrangement. I am also going to be using a good quantity of live rock, a small DSB in the sump, 2 or so inches of live sand in the tank, Seachem Denitrate and Seachem Purigen, so I'm not relying on the scrubber to do all the filtering.

Not going to use a skimmer, at least to begin with.

All thoughts and suggestions gratefully received.

Thanks in advance.

[inkidu]

Thats a lot like what I am using effectively.

http://www.freepatentsonline.com/5536398.pdf

Kind of hard to see but there is a bump at the end which keeps a certain level of water at all times.

There is also a gate right before the "bump" which forces the water to go underneath it.

The creator also uses bumps along several places of the bottom length and those line up with where the baffles direct water onto them. (creates turbulence)

If you have the time the patten is actually an interesting read.

Hope this helps.

[Rumpy Pumpy]

Thanks for that inkidu, I might add some sort of baffles to create a bit of turbulence.

[rygh]

So here is an enhancement thought:
Lower it, such that the water level in the trough matches the tank water level.
Use a propeller type powerhead angled slightly up, to push water directly from the tank into the trough.
You could get 1000 GPH for very few watts, and it would be super quiet.
The pump is much quieter, and there is no falling water on the return.
It really simplifies the whole thing.
With that much flow, should really eliminate turbulence concerns.
And since it is horizontal, no real need to have it raised anyway.

[SantaMonica]

I think it will work, especially if you increase the flow like you said. The increase in flow will help the water jump over algae islands that form, and, the narrow sides will helps do the same (water can't go around the islands easily). The more you could angle it the better. You can attached a drain pipe that keeps the flow quiet.

For comparison: Your 50 gal tank would need 50 square inches of two-sided screen; you now have 100 square inches of two-sided screen, which is really 200 inches of one-sided screen. You have 38 X 2 = 76 watts of light for a 50 gal = 1.5 watts/gal. Very good.

The limiting factor in yours is flow, but since you have twice the area and three times the light needed for a 50gal, and since the trough is narrow, it should work good. And you always have the option of increasing flow for much more filtering:

http://www.radio-media.com/fish/UserJohntanjmOnSG-15.jpg

[Rumpy Pumpy]

Thanks for the input SM.

I'll update the forum with it's progress.

[180rftank]

do yourself a favor and increase the angle as much as possible. I too have a horizontal. It worked ok, grew some algae, but then when I increased the angel, it really took off!

[Rumpy Pumpy]

do yourself a favor and increase the angle as much as possible. I too have a horizontal. It worked ok, grew some algae, but then when I increased the angel, it really took off!


Thanks for that, I will.

For now I've cut and fitted the tiles and upped the flow a little bit. It's now at around 2/3s capacity.

Should be fitting the lights tonight.

Vid here

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

[Rumpy Pumpy]

Update on this.

Filled and salted tank, acquired 40kg (90lbs) or so of live rock and a good quantity of live sand from a local guy who was shutting down his tank.

Got scrubber going (ended up with 2 x 30 watt tubes as the 38 watt ones were too long). 18 hours on, 6 off.

Let it bubble for a couple of days, threw in a dead prawn on day one, it rotted nicely and was falling to bits by day 3. No ammonia detected which I figure was a good thing. No nitrite or nitrate at that stage either.

Day 3, removed remains of prawn and added a pair of baby clowns and a small yellow tang. Other life that came with the rock/sand includes a couple of snails, some sand stars and some mushroom anemones.

Been feeding one cube frozen food per day since fish added (3rd day today)

Still no detectable ammonia or nitrite, nitrate starting to appear though (one test kit says trace, another says about 5, give or take)

Not a hint of green in the tank or on the scrubber.

Hey ho! Everything seems happy enough though.

[Rumpy Pumpy]

Today I have some brown splodges.

Quite a lot of em.

[SantaMonica]

Brown = high nutrients. Let it fill the screen, but only clean half at a time, since you want to always filter the ammonia.

[Rumpy Pumpy]

Brown = high nutrients. Let it fill the screen, but only clean half at a time, since you want to always filter the ammonia.


I can't find any ammonia or nitrite, I guess the nitrifying bacteria in the rock and sand is taking care of that.

I'll clean half when it covers the screen as you suggest.

Thanks

[sklywag]

You added livestock on the third day? You should have let it cycle for several weeks. Or did I miss something?

[rygh]

You added livestock on the third day? You should have let it cycle for several weeks. Or did I miss something?
He said it was live rock/sand from someone shutting down their tank, so if fresh, would have a good bacteria population already.
In that case it is actually better to add livestock reasonably soon, before existing bacteria starves.

[Rumpy Pumpy]

You added livestock on the third day? You should have let it cycle for several weeks. Or did I miss something?


Yep, and I had intended to do a fish-less cycle and let it sit for a month.

But after 3 days with rotting prawns and no ammonia spike I decided to take the chance.

So far so good.

[Rumpy Pumpy]

Quite a lot of brown now. Going to clean it tomorrow.

Thing is though, I suspect that my ceramic tile (reverse side) screens are not providing a very good surface for algae to adhere to.

They feel nice and rough to the touch but I fear it is the wrong sort of rough as just touching the surface causes the the brown stuff to come off straight away.

I'll persevere for a bit but I reckon I'm going to need some roughed up plastic canvas on this

Also I'm getting some algae in the tank now, including some hair algae, which is being cleared straight away by snails and hermits, but still... if it's growing in the tank, it should be growing on the screen.


I've also spotted a bit of bubble algae. Will the scrubber stop that spreading once it's properly established?

[SantaMonica]

If your scrubber is strong enough, it will beat bubbles.

[Rumpy Pumpy]

Here's where it is today

Vid 1 (with one of the tubes and reflectors removed to allow decent view)

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

Vid 2 (with the flow turned off so you can see the growth)

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

It's been running for 10 days (but there was no detectable nitrate for the first 2 or 3 days)

Two of the screens were cleaned on Monday, the other two have not been cleaned yet.

Is this on the right track?

You can see that on the first screen there is a large area of no growth around the inlet, I'll have to do something about that.

[SantaMonica]

Is not bad. For a smaller tank it may do the job.

[Rumpy Pumpy]

Bit of a breakthrough today, lots more growth on the two uncleaned tiles, getting quite thick now

AND... the nitrates are falling.

They went up to 10 ppm a couple of days ago and today tested at below 5 (2 separate tests)

There is some Seachem denitrate and a lot of live rock & sand in there too but I am sure that at least a good amount of this decrease in nitrate is due to the scrubber (since it's occurred as the algae has started to take off.


Very pleased with this so far.

[Rumpy Pumpy]

First proper cleaning (large photos, click links to view)

The two tiles that were cleaned last week (http://img.villagephotos.com/p/2010-5/1356287/photo%20136.jpg)

And the two that have not been cleaned before (2 weeks) (http://img.villagephotos.com/p/2010-5/1356287/photo%20137.jpg)

Tiles reinstalled in scrubber (http://img.villagephotos.com/p/2010-5/1356287/photo%20139.jpg)

Yield after draining (http://img.villagephotos.com/p/2010-5/1356287/photo%20140.jpg)

[SantaMonica]

Good start. Up the cleaning so that each screen does not go uncleaned for more than 10 days max, preferabley 7 while it's still dark.

[Rumpy Pumpy]

Something else I noticed too when I was cleaning the tiles, there are loads (millions probably) of mini pods living under the tiles on the acrylic base of the scrubber. I left the pump running while I cleaned the tiles to wash them out but most were not dislodged (the fish made a quick meal of the ones that were). I left them for now as I figured they might grow out under there and provide a better meal as bigger ones next time I clean. Should I have done this or are they likely to migrate to the other side of the screen and eat the algae?

[SantaMonica]

Don't know

[sklywag]

Feels a shame to rinse them down the drain seeing the cost a pretty penny for not that many.
Nice to see a horizontal working.

[Rumpy Pumpy]

Feels a shame to rinse them down the drain seeing the cost a pretty penny for not that many.


Yes it is.

I shall have to think about a method of harvesting them and placing them somewhere else to grow out.

[Gigaah]

I have a large number of pods in my scrubber bucket. I believe they are mainly isopods (the ones I can see anyhow). I clean the screens off normally and let them be. They do get on the screen rapidly after cleaning but everything seems ok with it. I imagine most scrubbers have them living inside somewhere as they seem very adept at holding on. Your particular design may be such as they have more room and suitable conditions for them to thrive on the scrubber its self.

I'd pretty much bet even if you could get rid of most of the ones you can see or get at it wouldn't make much difference as they would mutliply and accumulate that area again quickly. As long as your scrubber is doing its job I wouldn't be concerned about it. I have some pictures on this forum under "proof of pods" of the isopods I got..i suspect you have a similar type.

[Rumpy Pumpy]

Decided to clean it again this morning after 4 days.

The algae had completely covered the screen and was starting to grow long. It hadn't blocked or formed any islands but I figured it had probably gone far enough to warrant a clean.

Pic here http://img.villagephotos.com/p/2010-5/1356287/photo.jpg


Anyhow, scraped it all out and once drained it weighed 121 grams, 4 days after it's last cleaning.

Phosphate is 0. Nitrate is near to zero.

So in my official capacity as novice scrubber maker I am declaring this scrubber a success!

Many thanks to SM and other for their previous research and advice.

[SantaMonica]

Excellent! Great growth, as I had hoped, because of the strong lighting (1.5 watts per gallon). And the large size of 200 sq in one-side (equals 100 sq in two-sided) for just a 50 gal tank, makes up for algae islands trying to block the flow. And finally, the narrow size keeps water flowing over the islands, thereby keeping islands from forming in the first place.