Plankton-safe sump pump?

[ezrec]

I'm looking for a design for a plankton-safe sump pump. Ideally, it should be able to pump plankton up to the size of 1cm without blending them.

Currently, I am setting up a test tank with Artemia (brine shrimp)
as my plankton models, since they are (a) cheap to grow, (b) fragile and (c) grow rapidly throughout my test size range (0.25mm - 1cm)

My initial testing will be with an adult (1cm) population of approx 200 Artemia, and a Hagen AquaClear 802 rigid impeller pump, set up as a sump with a 4 ft head.

Testing has shown that the 802 with a garden hose attached to
the output can produce the 4 ft head I would need for the 'real'
aquarium, at a reasonable flow (between 50 and 100 gph).

I'll report back on survival rates in a few days, but until then, has
anyone had success in finding planton-safe pumping techniques
that are in the 10 to 200 gph range at a 4 ft head? I am eager to
test a number of techniques, to help improve the state of the
art of our hobby.

Some ideas I've considered and discarded:

Archimedies Screw: 45 degree orientation: Discarded
Loop-of-Buckets: Large number of moving parts: Discarded
Air lift: Unable to provide sufficient head

Some promising ideas, but can't find a "hobby size" model:

Recessed impeller pumps: Low efficiency
Centrifugal screw pumps: (used for pumping live fish!)
Bellows pumps: (concerned about bladder failure)


Thanks, and I await your ideas!

 

[Anonymous]

Why you need such a high flow rate for the plankton pump?

Have you consider venturi pump? How about simple gravity flow method?

What wrong with 45 degree orientation?

 

[ezrec]

Why you need such a high flow rate for the plankton pump?

Because the plankton will be cultured in both the tank
and the refugium. By "plankton", I mean both phytoplankton
(ie micro algae) and zooplankton (ie coral larvae, micro
crustacreans, etc). Basically, everything that can live suspended
in the water column.

Have you consider venturi pump?

Yes - I have decided not to follow that, because of
(a) the low efficiency of venturi pumps over a 4 ft head, and
(b) *most* of the water column would pass through
the major flow stream of the pump itself.

How about simple gravity flow method?

Many hobbists appear to prefer to have their refugiums
under the tank (as do I!), and I would like to design a system
that allows them to do so.


Great questions!

I should have been more specific about the problem I was
trying to solve (keeping the plankton in the reef ecology instead
of a dedicated 'reactor') in my initial post. Sorry about that.

 

[ezrec]

Oh - one more thing. I want to culture diatoms in the plankton
mix.

I know, I know. You're thinking OH NO! Those ugly brown things!. And I'm thinking Yeah! Free food for my filter feeders!.

I can deal with scrubbing the glass.

 

[baxter]

I looked into this about 5 years ago check out http://www.discflo.com
Bert

 

[ezrec]

The discflo pumps are interesting.

Do you have a specific part number that you have used sucessfully in the past?

Or do you have a 'conversion' technique where you fabricate a discflo-style impeller and attach it to a conventional powerhead?

 

[Anonymous]

How the discs are held together with an opening in the middle without any inter-disc support will be something I am interested in. If there is any inter-disc support, it will be a potential hazard to the planktons, similar to the impeller of a powerhead. Do you have any info about how the discs are held together?

 

[baxter]

I'll have to see if I still have the pump. After looking at the info on their site I modified a Dolphin pump.
If you look on the site you can see how the various impellers are constructed.

 

[ezrec]

VERY interested in your modifications, and your experiences with it.

I'm currently back in plumbing phase, as I crashed my Artemia tank,
so I'm read for more experimentation.

--- Ezrec goes off topic for a while...

If you really must know, I found out the hard way that the silt in
dry Calcium Carbonate sand (ie crushed shells) is lethal to Artemia
(and probably other filter feeders).

The poor little things got all clogged up with silt. I could see little
"balls of carbonite doom" attached to their filter appendages
by naked eye, and under the microscope several had lethally
ingested silt, clogging their digestive tracts.

Interestingly, I did have some surviors. Out of the approx 300
Artemia before the crash, I had 14 survivors. Including one very
clogged up but still twitching one.

Well, survivors until the water changes and QuickFilter floss to get rid of the sediment. Then, survivors should be zero, and I start again afresh.

Next time, I'll wash the sand first.

Ya know, I'm starting to think an 'Artmeia' tank might be a good
introductory tank for people who think they might be interested
in saltwater. It would allow them to get all the plumbing up, get
them into the practice of water tests and changing, and have
something fun to look at while they save up for their $2000 Solaris
LED lighting system (drool).

If I can find an inexpensive plankton-safe pumping system, all
someone would need to "see if they have what it takes" to keep
a simple saltwater aquarium would be:

Plumbing:

* < 55 gallon tank
* A PVC siphon overflow (no tank drilling!)
* Some buckets with garden hose or PVC siphons as the
overflow intake, refugium, and sump.
* A plankton-safe pump (the problem at hand!)
* A garden-hose return

Substrate:

* Reef salt (wherever they can get it)
* Declorinator (Novium, Start-Right, air stone & bucket, whatever)
* 1/2" layer of calcium carbonate sand (ie argonite)
(in both the tank and refugium)

Lighting:

* Freshwater-class hood (dime-a-dozen)
* Flourescent "Grow Light" for the refugium

Bio Load: (subject to change, I'm testing...)

* Biozyme (or Live Sand) for initial bacteria
* One dead frozen shrimp
After that has cycled till the ammonia is gone...
* Chaeto in the refugium
After that has cycled until the nitrites are gone...
* A pinch or two of brine shrimp

Testing:

* Hydrometer
* Ammonia
* Nitrites
* pH
* Copper (to determine if they have to use DI/RO or Tap)
* Thermometer (and not one of those crappy stick-on-tank LCD ones!)

Total cost should be under $200, and something any high school
kid could do. The theory being is that you now have a 'play' setup
with an active, cheap, forgiving, and easily replaced bio-load that
simulates the chemistry of a reef setup.

And, once said newbie finds that they actually have the patience,
funds, and nerves of steel to "go reef", they have a cheap source of
Artemia!


(Oh, did I mention that I was also one of those 'said newbies'?
I figure that if I can't keep Artemia alive, I should really stay away
from the reef.)

 

[Anonymous]

I took a closer look at the drawing, and it is the same impeller used in powerhead, just not as aggressive. Some jacuzzi pump impeller is just like that. I guess you will need to test it with live plankton, but it certainly does not look very promising, IMO.

 

[baxter]

Take a look at all the drawings, there are some that are very different from a powerhead impeller.

 

[Anonymous]

Any particular link?

 

[ezrec]

I would love to get my hands on a screw centrifugal pump at
hobbyist size.

Or a friend with a block of PVC and a CAD/CAM machine...

 

[Anonymous]

I would love to get my hands on a screw centrifugal pump at
hobbyist size.

Or a friend with a block of PVC and a CAD/CAM machine...

Archimedies Screw: 45 degree orientation: Discarded

they are pretty much the same. The Arch's need the gravity to hold the water down. If you spin it quick enough, the centrifugal force will take over, as in the case of the SCP, and you can hold it at any angle you want.

What about propeller pump? The SCP is like a propeller pump with an extended propeller.

 

[ezrec]

Here's a picture of the screw impeller pump design I was looking at:

http://www.weirclearliquid.com/weir..._Screw_Impeller_Pumps_Screw_Centrifugal_Pumps

(Unfortunately, the smallest they have is a 3" output opening model!)

But your centrifugal Archimedies screw concept bears investigation! I'll see what I can make out of garden hose
and wood dowels in a fresh-water model, and see what's
needed.

The only "worry" is with the water catch for the output, but
maybe a pyrex Bunt cake pan would do the trick...

Propeller Pump: I'll have to look into it, but I am concerned that a propeller pump with back-pressure from the water head would cause shear forces - and we're back to blending.

The SCP is unique from a propeller pump in that the ends of the
blades seal against the casing - preventing the plankton from being sheared by the blade ends.

HMMMMMMM.....

I wonder if *trimming* the blades of a 'classic' impeller design would allow more plankton to survive, yet still have sufficient
head. The theory is that the plankton would come in via the
intake, be flung towards the walls, but the shorter blades would
cause lower shear forces, at the cost of higher turbulence
and lower head.

Time to get more cheap used powerheads at the LFS![/url]

 

[Anonymous]

But your centrifugal Archimedies screw concept bears investigation! I'll see what I can make out of garden hose
and wood dowels in a fresh-water model, and see what's
needed.

Istead of a cylindrical wood dowel, use a cone-shaped "dowel" and spiral the hose around it. For a matched diameter hose with the cone, you practically have the same SCP, just that the housing rotates with the impeller.

 

[ezrec]

Update:

I've done some more research, and of the commerically available
aquarium pumps, the Tunze Turbelle extern pumps seem to
be the best 'plankton safe' pumps available.

I'm still looking into DIY projects, and will report here as I
test, but I'll save up for a Tunze and report back in this thread
once I've tested it.

(Unless, of course, someone would like to loan me a
space Tunze pump for a week. Like that would happen!)

 

[Anonymous]

Wouldn't a simple slow moving piston with flapper valves be good enough?

 

[Anonymous]

PLB, he want 50 to 100 gph. Need to have a big piston for that.

 

[ezrec]

Not to mention that flapper valves are unreliable if they become
coated with biofilms. (Which is one of the reasons why we don't use
check vales in our aquarium plumbling).