Tuesday, January 06, 2009

Happy New Year

First I'd like to say Happy New Year to all readers of my blog and website.

Next I thought I would add the following email I received from someone the other day about their pond planning:-
This filter stuff is getting confusing- I read Skippy's diy biofilter site. His claims are that his filter never needs cleaning, and that prefilter not necessary. I am told by others that a skimmer is a good prefilter, and that a commercially available biofilter falls unit is adequate. I do like the idea of a trickle tower,along with a traditional biofalls unit. Can your trickle tower or a commercially available one be incorporated either before or after a biofalls filter? How are the connections made? I am more inclined to buy these and connect everything rather than a diy configuration. Thank you Steve p.s I plan to build a 10x11x2-3 ft pond w/5-7 koi/other fish/plants
My reponse:-

Hi Steve,

I can sympathise with you!

Yes I also thought that a filter needs cleaning reasonably regularly. I
once wrote to the Skippy site and asked them the same sort of question,
and they said that a prefilter will help to prevent large amounts of crud
getting into the bio-filter.

That's why I designed my own DIY bio-filter to employ a pre-filter before
going into the main biofilter unit, and even then it has a section at the
bottom which I call the vortex area, where I angled the inlet pipes to
make the water spin around so that crud settles out into the large bottom
drain hole. Look at the photos on my site to see what I mean.

Both the pre-filter mechanism and the vortex section are quite good at
removing larger sediment, then the cleaner water goes into the bio-filter
media (green scrubbies) where the bacteria do their job to break down the
ammonia in the water.

I clean the pre-filter every few days, and drain the bottom section every
week, but the main bio-filter I generally leave alone and only actually
dismantle and clean once a year.

You will see that my bio-filter then exits the water into a homemade
trickle tower, i.e. the water comes out of the top of the bio-filter and
simply trickles down through some lava rock in the green trickle tower.

I would recommend that you get your pond setup and working with some basic
fish and plants to establish a good natural balance before you spend lots
of money on Koi which are generally far more sensitive creatures to
imbalances in the pond, or disease.

Also make sure that whatever filter you use (bought or DIY) is sized
sufficiently to cope with the amount of sewage (ammonia) the fish will
produce. Koi are voracious eaters and therefore produce a lot more
excrement than smaller fish! Small fish ponds with the traditional
goldfish can usually keep up with the natural filtration and biodegrading
of fish poop without the need for water pumps or bio-filtration. But not
so with Koi.

So the filter must be able to cope adequately. Another thing I say to
people is not to skimp on the water pump. I recommend a solids handling
pump that does not clog up with weed easily, otherwise it will lose
pressure and you forever be removing it from the pond to clean it.

If you intend getting Koi, I suggest you do plenty of homework on the
setup of your pond, and talk to your local aquatic supplier for advice, or
frequent some of the online fish pond forums to learn as much as you can
before going for expensive fish. While a DIY setup can be perfectly
adequate for the task, if this is the first time you've owned fish and
setup a pond I think you would be better starting off in a simple way, and
getting used to fish keeping in a pond for a year, before moving onto
larger fish.

Alternatively if you have the money and wish to pay for a professional to
build the pond and equip it, and advise you then of course go that route
and get some nice koi from the start. It depends on you aspirations and
current experience.

Personally this is the route I have taken, with my pond in its current
form for about 5 years now, but my fish keep having babies, and the two
ghost koi I have are now monsters, so I've got to a point where I am
considering upsizing the pond, making it deeper, and re-equipping with
some more pro kit.

However, in all the time I've had the pond the DIY skippy has kept the
pond clear and clean (although blanket weed will tend to be a problem at
times, simply because my pond is not deep enough, so sunlight causes it to
grow too fast).

If you're going for koi, I would try digging deeper than 2-3 feet. They
will need the depth to swim in, and a pond that shallow may have a harder
time with green water in the summer, and may suffer from wide temperature
variations which heightens algae problems, and oxygen deficiency resulting
in the fish gasping for air.

This is why you will often see pro koi ponds with some kind of pagoda
providing shade and cover for the pond, to keep leaves and twigs out, fend
off marauding herons, and keep sunlight out so as to control the
temperature and photsynthesis of phytoplankton (algae) in the pond. If you
over feed the fish, you will end up with too much fish waste, or uneaten
food polluting the pond, and this provides nutrients for the phytoplankton
to feed on resulting in a bloom of these tiny living creatures. When
sunlight falls on them, they photosynthesize and turn from clear
transparent bodies to green, and this is what makes the pond water become
green and unclear, and now suddenly you can see only the plankton (algae)
so preventing you from seeing your fish, and in extreme cases using up all
the oxygen in the water, so suffocating the fish, causing them distress
and even death. Things have to be in pretty bad shape for this to happen,
so don't worry about that too much. The thing to understand is the natural
balance you are trying to achieve.

If you're trying to stuff too many big fish into too small a pond, with
too much sunlight, too much food, and not enough plants to oxygenate the
water to use up the nitrates before the algae can, that's when the trouble
begins! And that's when you need a bio-filter, pumps and venturis to
oxygenate the water and help mother nature keep the balance with good
bacteria to maintain a healthy pond.

There's a few things for you to think about. If you have any more
questions I would be happy to answer them.



At 9/9/09 1:55 am, Blogger Megaprimal said...

Jim, not sure if you are still monitoring this blog, or if this is the best way to contact you but hopefully this message will find you one way or another.

You have posted a great deal of detail about your experience with the "skippy's bio filter" and though you could possibly add some additional insight to my setup. I get the impression you enjoy the science and mathmatics involved with the balance of ponding, as well as the experimantation and feel we share this as a common bond.

I built a pond last spring using a variation of the Skippy Bio filter. All has been well until roughly 3 weeks ago. My water has been crystal clear following the inital 45 day (or so) cycling period, and my fish have always seemed healthy and happy.

Continued next post...

At 9/9/09 1:56 am, Blogger Megaprimal said...

3 weeks ago the water started to turn pea soup for no apparant reason. My fish have not shown signs of stress, and tests of the water show normal PH and no identifiable ammonia, yet the water has not cleared in this time.

This past weekend, I started to investigate... I have a 1800 (US) gallon pond with roughly 300 gallons of filtration. It is a unique setup, but the water is pumped into a skippy style filter, through 2 inch pipe into a 5 foot deep "box".A little over two feet of the filter is under ground with the remainder of the 5 feet framed with landscape timbers. The whold enclosure is lined in EPDM pond liner. At the bottom of the filter I created a "T" and piped off to two 90 degree fittings to create a vortex. There is roughly 18 inches of empty space above this to create a pseudo vortex filter.

I positioned a peice of "egg crate" at that 18" height and filled the remainder of the bio-filter with skippy's own sponges. I used 7 bags (15.1 cubic feet) although the sales rep I spoke to recomended 10 bags for the 300 gallons (23 cubic feet). Above the filter media I positioned another peice of egg crate, and covered it with roughly 4 inches of lava rock. This acts as a plant shelf on top of the biofilter as the water exits over the waterfall.

The water rises a little over 5 feet to the top of the bio filter, and it is a 37" x 26" rectangle. I am using an external pump rated at 1500 GPH (US) so I am turning the water over slightly less than once every hour. I have calculated the contact time for the filter at roughly 6 minutes. In addition to the plants in the biofilter, I keep a fair number of plants in the pond as my fish are not yet large enough to do any real damage.

continued next post....

At 9/9/09 1:56 am, Blogger Megaprimal said...

As I stated earlier I started investigating the green water this past weekend. I plumbed a 1.5" drain pipe to extend to the bottom of the biofilter and attached a hose bib just above ground level when the pond was first built. I have been diligent in draining off water weekly (or more) and have noticed that the water removed is typically as clear as the pond water. I will drain the biofilter with the pump running but not a great deal of pressure flows.

This past weekend I did the same, and decided to syphon some water from the top of the filter at the same time. I began poking the sponges with a short piece of garden hose while syphoning water off the top and was disgusted at the blackness of the water which was released. I decided to attach a pump to the drain outlet of the filter, and found that when "backwashing" the filter and running my normal pond pump on the high speed (3000 gph) the water released was dark brown to black at times.

While investigating, I also noticed that the sponges which were visible appeared to be caked with sludge, and poking them with the syphon tube produced a most disgusting black water.

From reading your posts, I am unsure if you settled on a seperate "pre filter" or are using the "vortex" in this capacity. My current setup makes use of an external pump and a "lake screen" which is a three foot piece of 4" pvc pipe with a nubmer of 1/8th to 1/16th inch slits down the length to draw in water, and I am unsure if this is adequate for a "pre fitler".

I have thought about adding a seperate solids filter, by creating a 3 foot tall 4 inch PVC tube filled with "bird netting" prior to the water entering my bio-filter. This will only produce about 7 gallons of additional filtration, but the bird netting could be easily removed and rinsed as it became clogged with debris (not easily performed with the actual media in my bio filter). I could also plumb multiple tubes in parallel to distribute the load.

My other thought was to add additional bulk media to the bio-filter. I am considering the addition of bioballs, additional sponges, or 1.5 inch cubes of matala in varying densities. I am also considered adding spring-flo media to the lowest 18" of the filter and modifying the plubming to allow for easy backwash of the entire biofilter using the 3000 gph pump.

I wanted to get your feedback and opinons of each of the suggested enhancements, prior to undertaking any major changes. You can email me at steve.brauner@raymondjames.com, but I would ask that you remove this address prior to posting my reply to your site if you so choose.



At 6/11/09 11:07 pm, Anonymous MagicJack said...

Thanks for the homemade bio filter advice. Really enjoy visiting the pond when I get a chance.


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