Santa Monica 25 Nano Scrubber

[SantaMonica]

I'm coming up with the requirements of a 25 square inch nano scrubber that will sit above a nano display, and drain back into it. It is more plug-and-play than the 100, and will be designed for first-time tank owners who don't want to understand how it works. Here is what I have so far:

2 screens, about 4" (140cm) wide X 6" (210cm) tall each, with one light in the middle. Will need to flow about 4 X 35gph X 2 screens = 260 gph (988 lph) total.

Will attach to the side/back/top of a nano, but will be up higher, to get better draining.

The top of the scrubber will come off, and allow you to pull one screen out at a time for cleaning. Not sure yet if you should have to turn off flow first; if there is a valve on each screen, you should be able to turn off one screen while leaving the other one flowing.

Probably should include a timer for the light.

Will include the pump; one that can go into the display, or into the back ("sump") area of a nano. I'm not sure that a self-priming pump, placed in the scrubber, would be feasible, due to size and design hassles; a pump that strong would be heavy and big (bigger than the scrubber). So I think a regular pump in the display is better. If it's in the tank, there's no chance it would lose its prime (which would kill the screen), and, it would otherwise be of much more reliable construction, and much quieter too since it's under water.

One important point is that the pump can't be allowed to empty out the display by accident; in case of a problem, the pump should only empty out a half inch (1 cm) or so of the display water, just as HOB self-priming pumps would do. One way to do this is to put a hose on the intake of the pump, and set the pump on the bottom of the display; attach the end of the intake hose at a place up near the surface, maybe with suction cups. Or maybe use a stiff intake pipe instead, and have it go up like a snorkel, but just below the surface. If the user forgets to top off, the intake would start making noise as a reminder.

Mounting: Since it will be higher than other HOB devices, it will need to be on the sides of the tank, near the back. This will allow the lid to be raised without knocking the scrubber. Also, I don't think a regular HOB mount will be secure enough, because it's too easily knocked off (especially since the scrubber is higher). It's probably best to attach the scrubber (somewhat) permanently to the display. I'm thinking maybe double sided tape on the black part of the back of the nano; the tape would hold a large vertical plastic plate, and the plate would extend up to hold the scrubber. Or, a rigid strap across the back of the tank, with a clamp that tightens down on the corners, sort of like a vice. One last option would be a free-pivot mount, attatched to the top of the lid, that works like a seat on a ferris wheel: as the lid (and scrubber) is raised, the scrubber would rotate to keep itself vertical. It would do this because of a weight placed on it's bottom side.

In addition to the water tubing going into the scrubber, and a drain tubing coming out, there will also be an emergency overflow tube near the top of the screens. This will be for times when the user forgets to clean and the drain fills up. At that point, the overflow drain will handle all the flow forever, until the drain is cleaned.

Trying to find a price point for such a scrubber, if it includes pump, timer, tubing, bulb, mount, everthing.

[johnrt]

Hi:

You might want to make a platform for any brand of nano tank to sit on, that has a upright back with a shelf at the top for the scrubber to sit on. The weight of the tank would make the shelf stable and you would not be locked in to any particular brand of tank.

You could make a variety of stands, with suitable sized scrubbers, for standard sized tanks up to say 30 gallons all based on the same basic design, just by changing the dimensions and pump size.

Cool what? John T

[SantaMonica]

I thought of a similar version of that idea; A mount that slides under the nano, using the nano to hold it down. It would reach up and over the tank and hold the scrubber there. But I'm not sure if the nano would wobble or not. Your larger shelf version would stop any wobble, but I don't know if it would fit into the more elaborate nano-cabinets that I've seen.

[rygh]

Hmm.
I am thinking that not too many people will want a sizable cube placed up above a nano, or another pump inside it.
And for that 4+4= 8" screen, according to your calcs, isn't that a 256 GPH pump? Maybe less since one sided.
Still not tiny, for something that needs to go inside a nano.
Basically, the usual point of having a nano is either serious lack of space, or wanting an esthetic "minimalist" system.

I might suggest making a mini-ATS-SUMP instead.
So you make it a bit bigger, with a reservoir in the bottom for water and the pump.
Placed below the main tank, with a simple siphon system.
Definitely would need an automatic pump shutoff on water level.

You could even do something really fun, like make a fully sealed system.
Screens inside a fully sealed box. A bit like an ammo-box with clear sides. Light outside.
You would need a tiny air pump as well, to get the same waterfall effect.
Cleaning might be a hassle. Maybe not, with a couple of valves and the right opening system.
But installation would be a breeze, and you could easily put it under tank in a cabinet.

[SantaMonica]

Some good points.

It will be about 8 X 3.5 X 4. All the people so far who have built a scrubber for their nano's put it either on top, or in back. None of them put a sump in. Therefor I really don't think too many nano people would want to get a version that sits below the tank, even if it is it's own sump. Plus the siphon will end up stopping, and you'll loose your filter. A sump version might be a good next-step, however, if it had two pumps: one for the return, and one for continuous circulation on the screens. That way a broken siphon won't hurt anything. But this is a lot of space and money, which is why I don't think it would qualify as a simple nano device.

If I put all the flow on one side, I can probably get the flow less. I currently have it figured as going on both sides of the screens, even though they are one-sided.

I think I see what you mean by a sealed box, but I don't think having bubbles will give you any growth. Certainly not like a waterfall. But I'd like to see someone else try it

Anyways, I just finished a melt test, to see what happens when the 27watt light gets put into an almost-closed black acrylic box: It got hot, but no melting even after one hour. In operation, it would have more ventilation, and clear acrylic, which won't get as hot.

[rygh]

The reason it is not hot is probably because all the heat is going into the water.
So you end up with a 27W heater that is on 18 hrs a day. Could be an issue on a nano.
Definitely needs ventilation. You could make it more like a square donut, so sealed around the water, but center light section open on top/bottom.
You may want screen on all 4 sides at that point.

So on the sealed box, I was envisioning it was full of air. So it would have the same waterfall type effect. Not bubbles.
You have tank -> water pump -> pressurized ATS box -> usual bottom overflow -> back up to tank, (pushed up due to pressure)
The air pump keeps ats box mostly full of air. The air displaces the water down to the bottom of the screen, to the overflow out.
Beyond that, at the bottom, the small bit of air will naturally exit out with the water. (bubbles in the tank a minor concern).
Or you could get fancy with a tiny air return line at that point, or even a float switch to turn the air off.
Technically, a venturi might work on the pump, instead of a dedicated air pump. And from another thread, the froth may help.

[SantaMonica]

HOT = Hang On Top

[rygh]

Hot = not cold. :-)
I was commenting on your temperature test, not positioning.

[SantaMonica]

For the test there was no water, which is worst case. And I current have a sandwitch design, with light in middle, and screens on sides. Will be only about 3.5" thick. The center light/box will lift out for glass cleaning

[rygh]

BTW: On the pump priming issue.
If you put the pump below the water level, no real need for self priming.
You do need to prime the pump, but it is pretty easy, and you only need to do it once.
And that is even if ATS is above, and intake goes over tank edge.
So you could even have a single piece integrated ATS/pump holder/stand for behind/next to the nano. All made of acrylic.
Acrylic sits on table, acts as stand + ATS. Pump is on the bottom, below water, and ATS is on top.

BONUS SEMI-RELATED TIP:
If you have a plumbed external pump, for ATS, sump, closed loop circulation, etc.
Get a pump that is capable of submerged or external, and install it in a bucket of fresh water!
So pipes go in/out, and pump is submerged in the water. Tank water is separate from bucket water.
Great for reducing noise. - All that water really deadens pump noise.
Great for thermal problems. - A lot of heat from the pump goes into the fresh water, and out through bucket walls. Way better than air.
Great for maintenance. - When disconnecting pump for cleaning, it always spills. But this way, already in a nice bucket.

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