Reconstruction of Pond: Bottom drain or no?

[dweav44]

This is fun!

Originally Posted by tadpole

Even though they are called 'Gravity Fed', the water is not going to move through the drain without a pump creating the flow. I just don't believe that the terminology is accurate, even though it is accepted in the Pond industry.

The only reason water flows into the filter from the pond via gravity is because the pump is pumping water out of the filter. This system isn't a vacuum per say. The filter or settlement chamber has an open top. Water ALWAYS finds its level. If the system was closed the yes it would be the pump creating the the flow.

If I were to shut off one of the filter pumps the water would stop moving to the filter. If then I were to open one of the cleanout valves at the bottom of the settlement chamber and let the water flow out freely to the ground then the water would start flowing again from the pond to the filter and out. Yes, I would be losing water, but the water would be exiting the pond at the same rate it was exiting the settlement chamber until the pond water level reached the same level as the entry into the settlement chamber. There isn't a pump moving that water, it is... gravity. The only purpose the pump serves is to be that 'open valve' and send water back to the pond.

Originally Posted by tadpole

I want to make it clear that bottom drains DO WORK, and quite well. What I have a problem with is that the use of a bottom drain indicates a bare liner Pond which is a completely unnatural aquatic environment. There is no way to approximate a functional aquatic eco-system in a bare liner Pond.

We are talking about koi ponds right? Just to make sure we are on the same page. The most popular pond for koi is a bare liner pond. As stated earlier it IS unnatural. That is why there are biofilters. And no need to approximate good quality water, there are lots of tests you can run to make sure you have good quality water. I don't understand the need for other living things in the water. Some of the best show koi are shown in bare liner ponds.

Originally Posted by tadpole

The primary purpose of a gravel bottom is not to provide bio-filtration, but to provide habitat for a wide diversity of invertebrates that are crucial in the reduction of organic waste and debris to simpler forms that are subsequently used as food by other invertebrates.

It does act as the biofiltration. You wouldn't have biofiltration without it.

Originally Posted by tadpole

the aquatic environment will never be in balance.

What exactly does this mean?


What Bbentler, if he has even looked at this thread lately, is asking for is something that is easier to maintain. Bare liner pond with bottom drain, in my opinion, is easier to maintain. No cleanout whatsoever.

[CJF]

I believe a bottom drain is the single most important thing
you can do for your pond. We have a gravity fed system.
It's a DIY filter system that works extremely well. Our pond is
13 years old and has never had to be emptied for cleaning.
I've read many forums, and never have I ever read that
someone was unhappy with their bottom drain...

[tadpole]

We are talking about koi ponds right? Just to make sure we are on the same page. The most popular pond for koi is a bare liner pond. As stated earlier it IS unnatural. That is why there are biofilters. And no need to approximate good quality water, there are lots of tests you can run to make sure you have good quality water. I don't understand the need for other living things in the water. Some of the best show koi are shown in bare liner ponds.

Actually, I was responding to Bbentler's original post in which he stated that what he was reconstructing would primarily be a Water Garden with maybe 1 or 2 Koi. I never mentioned approximating Water Quality, it must be periodically tested. I did mention approximating a functional aquatic eco-system in which water quality is only one parameter.

In my almost 15 years of being exclusively in the Pond construction and maintenance arena, I have become familiar with all of the apparatus that has been introduced for Water Quality control, from Degassing Columns to Protein Skimmers, from UV Clarifiers to Ozone Generators.

With some Koi selling for thousands and even tens of thousands of dollars, it is understandable that the purchaser of these fish would be maybe a little paranoid as to preserving the health of an investment of this size. Hence, the attempt to create a near sterile environment using the latest technology to protect this investment. I know that I would use everything available to protect this size of investment.

There is a need for other forms of life, both plant and animal, in the water column. They comprise the Food Web: from the bacteria, which colonize all of the surfaces below the water line, up to the higher invertebrates that serve as food for the fish.They provide the checks and balances on both a chemical and biological level keep the Pond's ecosystem in state of equilibrium. Nature certainly feels that this biodiversity is necessary as do most scientists, who judge the health and stability of any ecosystem by its Biodiversity.

[dweav44]

Tadpole -

It sounds like you are saying that you can't have a nice watergarden or koi pond with a bare liner and bottom drains. Is that what you are saying?

I want to make sure we are clear on these things. I don't want anyone to be misled.

Originally Posted by tadpole

The installation of a bottom drain for a Pond is solely for the benefit of the Pond owner, it is definitely NOT beneficial to any resident fish.

They ARE beneficial because they keep the bottom of the pond clean. They get the crap out or whatever else is in the water. It is sent to filtration to be removed.
You don't have to have gravel to enjoy koi and plants. Biofiltration takes care of the biological balance you talk about.
Why do you need other organisms in the water? Plants and koi do just fine without the extra stuff in the water.

Originally Posted by tadpole

For a bottom drain to work properly you can not rely on gravity.

Most are gravity fed to filtration.

Originally Posted by tadpole

The addition of a bottom drain will also preclude the use of a gravel bottom, which is also quite important for biological balance.

You are implying here that without gravel you can't have biological balance. Not true. Biological filters.


There is a reason people put their expensive koi in a bare liner pond with bottom drains. It is better than gravel bottom. A koi pond isn't sterile, there are lots of beneficial bacteria and other life in the water.

I am not saying that ponds with gravel and no bottom drains are useless. I just don't like the cleanup necessary.

Bbentler's main point and question was that he wanted a simpler maintenance plan. draining and cleaning isn't simple.

[tadpole]

I will try to further clarify my previous postings.

Bottom drains DO greatly aid in keeping a pond's bottom free of any detritus. They DO reduce required maintenance.

They really DO NOT benefit the fish. Koi (Cyprinus carpio) are native to Lakes and slow moving rivers that are high in nutrients and subject to frequent algae blooms. They are able to tolerate low Oxygen levels. This is why they are raised in mud ponds, as this most closely approximates their native habitat. They are by nature onmivorous bottom feeders. It stands to reason that a pond with a clean bare bottom would not be a Koi's preferred habitat.

That being said, it should also be noted that Koi will quickly adapt to a wide range of habitat environments. This ability to adapt has caused them to be outlawed in most of Australia and New Zealand. Even the State of Maine prohibits the personal possession of Koi except by special permit. They have become such a problem in Australia that the government is actually considering introducing the KHV virus into the waterways to eradicate them. So as long as the water quality is not toxic and they are well fed, Koi will adapt.

The establishment of a stable functioning nitrogen cycle through the establishment of adequately sized colonies of nitrifying bacteria i.e.biological filtration, is only a part of the total biology of an aquatic eco-system. Other balances must be achieved through adequate number and diversity of plants and through the availability of micro-habitats for colonization of various microorganisms required in establishing the all important Food Web. These micro-habitats are formed when the sides of a pond are covered with rock and the bottom is covered with gravel which should be coarse such as Egg Rock and only 2 inches deep. Any deeper CAN cause problems.

In summary;

Koi can survive in any pond, with or without a bottom drain.

An aquatic eco-system is a pond, but a pond is not necessarily an aquatic eco-system.

The real question to be considered is: What does the customer want? Are the fish to be the total focal point of the Water Feature or is an aquatic habitat that will attract other various forms of wildlife more to their liking? Maintenance will be required on any pond. The further that you move away from the eco-system concept the less maintenance will be required, but the more artificial and unnatural the aquatic environment becomes.

[CJF]

tadpole, How big (gallonage) is the average pond that you install and do you empty
your ponds yearly, and clean the gravel
and rocks and refill the pond in the backyard ponds
you install?
Do you also install uv lights?

[tadpole]

How big (gallonage) is the average pond that you install

Over the years, I would guess that the average is somewhere around 1500-2000 gal. More recently, partially due to the DIY craze, the average is probably more like 3000-3500 gal. Number of new installs has drastically decreased in the past couple of years. Probably the economy and DIY.

and do you empty your ponds yearly, and clean the gravel
and rocks and refill the pond in the backyard ponds you install?

My installations are designed to go 2 to 4 years without cleaning. Cleaning frequency is also directly influenced by the interest (or lack of) the customer has in their Pond. I maintain and service several ponds that were landscaper installed improperly. These usually require more maintenance and cleaning. I have ponds (my installations) located directly under Oaks and Weeping Willows (we all know what a mess these 2 make) that only need cleaning every 4 years because they were installed with multiple and/or oversized skimmers.

Do you also install uv lights?

Let's open another 'Can of Worms'. The answer is NO. In a properly installed 'Eco-system' Pond, they are unnecessary.

[CJF]

Tadpole, Tadpole maintaining a clean pond without
a BD is more maintenance.
Our pond is 2500 gallons has a BD (gravity fed system)
we also have a 200 gallon biological pond located 18 feet away.
The water travels back and forth each day between the bio pond
and the main pond. The water first goes through the three filter tubs,
when leaves the last tub it travels underground to the bio pond.
The bio pond is filled with vegetation and some
lava rocks, which scrubbs the water as it travels through
the bio pond before it makes it journey back to the main pond.

We have never emptied our pond for cleaning in 13 years. We are
also surrounded by hugs oaks and only use the skimmer in spring
and fall, when the trees are making a mess. The rest of the
season the skimmer is shut off.
We also don't have to vacuum. We clean the first filter tub once
or twice a week, depending on the time of year.

We also never use any chemicals at all (except salt in the winter)
and we don't use a uv light.

There are many ways to maintain a clean and healthy pond -- with a bottom drain or without one.

[tadpole]

I forgot to add that what may be standard maintenance practice for my geographical location probably would not apply to yours. Temperature Min/Max and duration of same will greatly affect the biological dynamics of any eco-system including aquatic. In this area, we rarely have sustained low temps. As a result, we have bio conversion occurring year round. On the flip side, we do have sustained high temps that can become problematic for cold water fish such as Koi and even Goldfish. I have seen many a small pond with basically half-cooked fish floating on the surface.

[tadpole]

What you refer to as a "bio-pond" is a form of Phyto-filtration, much the same as a Wetlands but on a smaller scale. The Brits like to call them "Veggie-Filters". They are great for giving water that final 'polish' by removing trace elements and compounds that a bio-filter cannot. I encourage all of my clients to include a wetlands filter (large Phyto) in their installations or to consider adding one to their present pond. Mine are installed as part of the main pond, not a separate unit.

I also do not use chemicals, except De-Clor and only Salt when conditions indicate.