Continuous Gravel Vacuum

[John >]

Been busy lately and have not had time for groups. As usual when I come up
to the next project I consult with the freshwater community for their
advice.

I am considering Netmax's Continuous Gravel Vacuum
http://www.2cah.com/netmax/diy_projects/vac/vac.shtml

I need to move 6,000 GPH to filter this tank. How much surface area do I
need in a 1" to 1 1/2" high UGF to allow this much water to flow? I would
prefer that this UGF plate be no more than 6" to 10" wide and up to 10' long

Some of you mathematicians will be able to help calculate this.

In order to keep small fish (1" to 2" long) out of this filter the grate
openings will have to be less than 1/8" square. Any idea's for the grate
material?

Thanks
JOhn ><>

[George Pontis]

In article >,
says...
> Been busy lately and have not had time for groups. As usual when I come up
> to the next project I consult with the freshwater community for their
> advice.
>
> I am considering Netmax's Continuous Gravel Vacuum
> http://www.2cah.com/netmax/diy_projects/vac/vac.shtml
>
> I need to move 6,000 GPH to filter this tank. How much surface area do I
> need in a 1" to 1 1/2" high UGF to allow this much water to flow? I would
> prefer that this UGF plate be no more than 6" to 10" wide and up to 10' long
>
> Some of you mathematicians will be able to help calculate this.
>
> In order to keep small fish (1" to 2" long) out of this filter the grate
> openings will have to be less than 1/8" square. Any idea's for the grate
> material?
>

6000 GPH ?
UGF 10 feet long ?

This is some serious setup. I am interested to ask what heating and lighting goes
with it.

Let's see what the water velocity would be at 6000 GPH through a 6" wide by 10'
long grate. 6000 GPH is 1.666 gallons per second. One cubic foot of water is 7.5
gallons. So 6000 GPH translates to .222 cubic feet per second. (Suddenly it does
not seem so impressive.) Over the proposed area of 5 square feet, the linear
velocity would be about half an inch per second.

That seems like a good number - not so much as to make it difficult for a fish to
swim over the grate, but enough to maintain a steady flow toward it. You would get
similar results with a 10" wide UGF that is 6' long. If you are not concerned
about aesthetics, why not just go with a screen of small enough mesh ? The square
section plastic grill used as a light diffuser, and sold at the home centers,
would make a good support for a screen. You would have to build a base to lift it
off the bottom of the tank, and the base would need to not leak too much. You
would also need some good support under the grill if you plan to put any rock or
gravel over it.

Given that the UGF is only 1.5" high, you will also need some kind of manifold
connecting to the pump inlet. A manifold will connect into the UGF at multiple
points to prevent pressure drop along the length of the UGF. The plumbing to the
UGF is not trivial if you are also limited by the 1.5" height. General rules for
pipe sizes would call for two 2" PVC pipes at that flow rate. Perhaps you could
stretch that a bit and use as few as six 1" pipes spaced along the length of the
UGF.

George

[John >]

> 6000 GPH ?
> UGF 10 feet long ?
>
> This is some serious setup. I am interested to ask what heating and
> lighting goes
> with it.
>
> Let's see what the water velocity would be at 6000 GPH through a 6" wide
> by 10'
> long grate. 6000 GPH is 1.666 gallons per second. One cubic foot of water
> is 7.5
> gallons. So 6000 GPH translates to .222 cubic feet per second. (Suddenly
> it does
> not seem so impressive.) Over the proposed area of 5 square feet, the
> linear
> velocity would be about half an inch per second.
>

OUCH all that math makes my head hurt. I figured I would find an
engineering type here, that's why I asked. Sounds like the sump idea could
work out OK. The 1" tubing to a 1 1/2" manifold to the pump sounds like a
good idea.

The tank is about 955 gallons approximately 10' X 4' X 4'
http://www.noahs-marine.com/Aquarium/Images/1000/Installation/kids.jpg
http://www.noahs-marine.com/Aquarium/Images/1000/Fill/P1280162.JPG

http://www.noahs-marine.com/Aquarium/Images/1000/Fish/P5020077.JPG
http://www.noahs-marine.com/Aquarium/Images/1000/Fish/P5020080.JPG
http://www.noahs-marine.com/Aquarium/Images/1000/Fish/P5020081.JPG

I don't have many current pictures with fish, because I have not been able
to get the water as clear as I want it. It looks like Lake Water now. I
currently have an 80 gallon drip/sump with 40 gallons of bio balls and 4" of
filter floss. It is taking care of the bio load just fine, but the water is
still not very clear. I am only moving about 300 gallons per hour through
the filter.

I am looking at 2 - Pentair Aquatics M4 Commercial filters and 2 - 120W UV
modules for a sealed system that I should be able to move 6,000+ GPH through
easily with 1 1/2" vacuum hose. The UGF sump in the bottom of the tank will
help remove detritus and all the other stuff that settles on the bottom of
the tank.

One of the nice things with Fresh Water Game Fish is that they are not too
picky about water temp / quality. Around here lake water temp is 34 degrees
in the winter and as high as 82 in the summer. We are more concerned about
keeping the water cool in the summer than heating in the winter.

I don't have enough light yet, I have two 8' - 2 bulb High Output Industrial
Florescent fixtures and two 4' - 2 bulb day light aquarium fixtures.
Between the murky water and the low light it is hard to see the fish in the
back of the tank on some days. I am working on three 400W industrial metal
halide low bay fixtures. That ought to create some algae problems [GRIN]

Current inhabitants are:
1 - 28" Tiger Muskie
8 - 4" to 12" Bluegills (brem)
8 - 6" to 15" Crappie
1 - 8" Perch
2 - 16" Walleye
1 - 18" Large Mouth Bass
12 - Apple Snails
on average 50 to 200 bait fish in the 1" to 4" range
We had 6 bullfrog tadpoles until we put the Bass in.

I am currently looking for a 10" to 12" Channel Cat to keep the bottom
clean. As soon as I get the additional lighting/heat I will add one or two
4" to 6" Painted or Snapping Turtles with a sunning log built into one of
the hatch openings under one of the MH lights.

Plant Life mostly fake because of the low light. I do have one small Lilly
Pad growing ok?

4000# Tank Stand is 100 - 40# - 8" cement blocks
900# 1" Acrylic Tank
1500# 1" to 2" Landscape Gravel
8000# Water

On top of the blocks are 2 X 8's on their side, 3/4 sturdy floor plywood and
1" blue styrofoam.

So far (6 months) the 6" concrete floor under the tank is holding up. The
carpet underneath will probably never be the same.

Thanks for your help
JOhn ><>

[George Pontis]

In article >,
says...
> > 6000 GPH ?
> > UGF 10 feet long ?
> >
> > This is some serious setup. I am interested to ask what heating and
> > lighting goes
> > with it.
> >
> > ...
>
> So far (6 months) the 6" concrete floor under the tank is holding up. The
> carpet underneath will probably never be the same.
>
> Thanks for your help
> JOhn ><>
>

Thanks for sharing the pictures and description. That IS one hell of a setup. The
picture with the kids sitting in the tank really shows the scale nicely.

Back to the math for a minute. (I knew it would come in handy one day.) You
mention a 1.5" manifold to the pump for your final setup. I think this is not
enough for 6000 GPH. Two in that size would the minimum. Think of it this way. For
1.5" pipe you can get around 40 GPM with the water moving at quick 7 feet per
second. You need 100 GPM ( = 6000 GPH ). A 2.5" pipe would be conservative, two
1.5" pipes probably usable. A single 2" pipe is undersized. OTOH, you might find
3000-4000 GPH is adequate to keep the tank in circulation and filtered. The pump
that you choose will probably have some gigantic inlet which you can use for
comparison.

[John >]

>> > 6000 GPH ?
>> > UGF 10 feet long ?
>> >
>> > This is some serious setup. I am interested to ask what heating and
>> > lighting goes
>> > with it.
>> >
>> > ...
>>
>> So far (6 months) the 6" concrete floor under the tank is holding up.
>> The
>> carpet underneath will probably never be the same.
>>
>> Thanks for your help
>> JOhn ><>
>>
>
> Thanks for sharing the pictures and description. That IS one hell of a
> setup. The
> picture with the kids sitting in the tank really shows the scale nicely.
>
> Back to the math for a minute. (I knew it would come in handy one day.)
> You
> mention a 1.5" manifold to the pump for your final setup. I think this is
> not
> enough for 6000 GPH.

Backup a minute. I apologize. Pentair Aquatics recommended their 14000
Quiet One Pump, and two filter units with the capacity of 3,000 to 6,000 gph
each. My assumption was that the pump would move 6000 gph. I am corrected
and now realize that the pump will only push 3,000 gph.. The inlet & outlet
on the filter units is 1 1/4" My current 1500 gph pump has 1" inlet &
outlets.

Back to square one...

JOhn ><>

[George Pontis]

In article >,
says...
> >> > 6000 GPH ?
> >> > UGF 10 feet long ?
> >> >
> >> > This is some serious setup. I am interested to ask what heating and
> >> > lighting goes
> >> > with it.
> >> >
> >> > ...
> >>
> >> So far (6 months) the 6" concrete floor under the tank is holding up.
> >> The
> >> carpet underneath will probably never be the same.
> >>
> >> Thanks for your help
> >> JOhn ><>
> >>
> >
> > Thanks for sharing the pictures and description. That IS one hell of a
> > setup. The
> > picture with the kids sitting in the tank really shows the scale nicely.
> >
> > Back to the math for a minute. (I knew it would come in handy one day.)
> > You
> > mention a 1.5" manifold to the pump for your final setup. I think this is
> > not
> > enough for 6000 GPH.
>
> Backup a minute. I apologize. Pentair Aquatics recommended their 14000
> Quiet One Pump, and two filter units with the capacity of 3,000 to 6,000 gph
> each. My assumption was that the pump would move 6000 gph. I am corrected
> and now realize that the pump will only push 3,000 gph.. The inlet & outlet
> on the filter units is 1 1/4" My current 1500 gph pump has 1" inlet &
> outlets.
>
> Back to square one...
>

That works out better... but you still need at least one 1.5" intake pipe. If you
have to reduce to 1.25" for the filter module then the pump output would be the
place to do it.

It occurs to me that you will actually have a big enough tank and enough
filtration that you could house a redtail catfish. You could amuse your clientele
by feeding it hamburger patties, buckets of large trout, whole heads of broccoli,
etc. Now that would be quite the sight. Not that I know anything about these fish,
only that they are always held up as an example of what is too big for any normal
aquarium.

[John >]

>buckets of large trout, whole heads of broccoli,
>
Yikes, it would probably eat all my current inhabitants.

Thanks for your input on the ugf for this tank. In this case it really
won't be used as a ugf, but an undergravel drain. I like the idea of 1"
tubes to a manifold, I was trying to figure out how to hide a single LARGE
tube.

Next have to figure out how to keep all the kids (fish) happy while I drain
down the tank low enough so I can climb in and do the work.

JOhn ><>