Any Tips/techniques for cleaning bottom of a pond?

[Gordo33]

Yes, but the ideal arrangement is to keep as much TSS out of any bio-filtration as possible. This is the reason for having a SC.

Ok so is this to maximize BB surface area to grow? What percentage BB in a pond is growing in the " dedicated" bio filter? It is my understanding BB grows on the liner, any rocks or gravel in the pond ,on plant roots and any porous fixtures (pump cages,plant pots etc). So I can see how a SC is important for a dedicated koi pond , that typically does not have a lot of plants, to minimize TSS getting to the bio filtration. From what I see on this forum most have gold fish ( therefore a lighter bio load) and most are planted. Am I correct to conclude if ammonia and nitrites are 0 ppm TDS is low then a heavily planted gold fish pond will thrive without a dedicated bio filter.

Since bottom drains are usually either 3" or 4", flow rate ranges have been determined. In your case, with dual 2" DIY BDs manifolded to a 1 1/2" supply line, you will need to experiment. You want the flow to be fast enough that debris does not settle in the plumbing yet slow enough that the debris will have time to fall out of suspension in the SC. Not that it will really help but a 3" BD requires at least 1500 gph and a 4" BD requires a minimum of 2500 gph. Adjusting the size of the SC to 10% of the flow rate will complete the configuration.
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In the pic you attached:
To make the flow work would both pumps need to be pumping at the same rate. If the pond pump is stronger than the pump after the SC the SC would over flow. If the pond pump is weaker than the pump after the SC the SC would be drained down. Seems a disaster waiting to happen if one of the lines clog causing a change in flow.

 

[Meyer Jordan]

Am I correct to conclude if ammonia and nitrites are 0 ppm TDS is low then a heavily planted gold fish pond will thrive without a dedicated bio filter.

If those parameter levels can be maintained without a bio-filter, then the answer is yes

In the pic you attached:
To make the flow work would both pumps need to be pumping at the same rate.

There is no second pump in the graphic that I posted. What you see at the bottom of the pond is the BD. The BD and SC are gravity-fed, not pump fed.

 

[Gordo33]

There is no second pump in the graphic that I posted. What you see at the bottom of the pond is the BD. The BD and SC are gravity-fed, not pump fed.

Thanks for clearing that up
In the set up with the BD line going thru the liner to the SC is there enough flow to pull debris especially larger debris up and then across? From what I read a true BD pulls water from a large radius from the BD location. For ex a 3 inch BD will pull debris up to 8 feet away. Do you know what the radius for debris being drawn to the BD for the pic you attached? Also how do you determine pump size for this set up. As you stated in a post here there are set flow rates based on diameter of the true BD.

With the set up going up and over the pond to the SC. The inverted U shape created by the tubing looks similar to aquarium over flows. My understanding the water flow is via SIPHON and is dependant on removing all the air from the inverted U. The issue with this set up is air can accumulate in the tube and potentially break the siphon . This would cause the pump to drain the SC and then the pump would fail. In the event of a power outage I assume the BD would continue siphoning the water into the SC draining the pond as the SC over flows.
Unless the bottom drain is pulling water from a large radius and can move large debris upward and across to the SC , I don't see the advantages of the pictured set up to the above liner BD set up I use.

 

[Meyer Jordan]

Thanks for clearing that up
In the set up with the BD line going thru the liner to the SC is there enough flow to pull debris especially larger debris up and then across? From what I read a true BD pulls water from a large radius from the BD location. For ex a 3 inch BD will pull debris up to 8 feet away. Do you know what the radius for debris being drawn to the BD for the pic you attached? Also how do you determine pump size for this set up. As you stated in a post here there are set flow rates based on diameter of the true BD.

With the set up going up and over the pond to the SC. The inverted U shape created by the tubing looks similar to aquarium over flows. My understanding the water flow is via SIPHON and is dependant on removing all the air from the inverted U. The issue with this set up is air can accumulate in the tube and potentially break the siphon . This would cause the pump to drain the SC and then the pump would fail. In the event of a power outage I assume the BD would continue siphoning the water into the SC draining the pond as the SC over flows.
Unless the bottom drain is pulling water from a large radius and can move large debris upward and across to the SC , I don't see the advantages of the pictured set up to the above liner BD set up I use.

I posted this graphic only to illustrate the recommended positioning of the BD, SC and pump in relation to each other. I certainly agree that using the 'up-and-over' approach for routing the intake is asking for problems. If a retro BD is used, I would strongly recommend that the intake be directed through the liner and wall of the pond through use of a bulkhead fitting. Note that in the graphic the 'up-and-over' approach is labeled "Alternate"
Another problem with any form of retrofitted BD is the shape of the pond bottom. In those ponds where bottom drains are part of the original construction, some slope is engineered into the bottom of the pond creating a slight funnel effect which aids in the function and efficiency of the BD. This sloping is not usually found in ponds that are retrofitted. Personally, I see no advantage in using a bottom drain in anything but a dedicated Koi pond, but that is for a separate discussion.
If your current set-up is working for you, great. I still question the use of the bio-filter as also the only mechanical filter.

 

[Gordo33]

. Personally, I see no advantage in using a bottom drain in anything but a dedicated Koi pond, but that is for a separate discussion.
If your current set-up is working for you, great. I still question the use of the bio-filter as also the only mechanical filter.

I agree with your comment about BD.
I don't remember the source but the reason I added the retro bottom drain was to improve circulation by pulling water from the bottom of the pond.

If your current set-up is working for you, great. I still question the use of the bio-filter as also the only mechanical filter.

My background prior to building the pond is with fresh water aquarium. All the filters whether hang on the back, canister or sump combine mechanical and bio filtration in the same housing. Yes they set them up to allow the water to go thru mechanical filter pads before moving thru the bio media. Back yard ponds to some degree are similiar to a an aquarium. It is a closed loop system. . My thought with the veggie set up is the root mass would play a duel role . The lower roots closest to where the water enters (at the bottom) would mechanically filter the water and the upper root system would act more as a bio medium for BB growth. Any fine suspended particles would also get trapped in the mechanical cartridge I placed in front of the outlets leading to the pond. In addition the heavily planted stream catches aa lot of finer particles before the water dumps onto the pond. As I mentioned earlier I do clean the veggie filter and the water parameters so far have been good. The fish and other wild life seem to be thriving.
I appreciate your input and am always open for suggestions to improve the pond.

 

[Meyer Jordan]

I don't remember the source but the reason I added the retro bottom drain was to improve circulation by pulling water from the bottom of the pond.

It has always been a source of surprise to me that the one main source of water mixing in backyard ponds is usually overlooked....the fish. Especially larger fish...adult Goldfish and Koi.

 

[morewater]

There was recently a show on National Geographic regarding just that phenomenon in the Worlds oceans, strangely (but when you actually think about it, obviously) the largest contributors to the movement of water wasn't the larger mammals and fish, but the smaller (ie. shrimp, jellyfish, etc.) due to the sheer numbers.

 

[Mucky_Waters]

Personally, I see no advantage in using a bottom drain in anything but a dedicated Koi pond, but that is for a separate discussion.

The advantage is simple,,, easier cleaning maintenance.
Dedicated koi ponds generally don't have plants in them, but in my pond more than 95% of the excess detritus that flows through my bottom drain and accumulates in my settling tank is dead plant mater and algae. Without a bottom drain "system" all that stuff would accumulate on the bottom of my pond and would be much harder to remove, or it would eventually break down and increase the DOCs and ammonia, nitrites and nitrates to my water. Having a bottom drain allows me to cleanly flush these wastes materials out of the water system while it is still in a more solid form that is easily removed. That is the advantage!

What I personally see as a distinct disadvantage is having a bottom drain (that is not gravity fed), going directly to a pump that purees that waste materials, that would otherwise settle on the bottom of the pond, and blends them up and makes them much harder to capture and remove mechanically and sends them (a) back into the water system, or (b) into a bio filter where they tend to clog and contaminate whatever bio media is being utilized.
Without a settling tank, sieve, or some other efficient mechanical filtering system directly after a gravity fed bottom drain you are better off without a bottom drain at all. Better to just allow the waste material to settle on the bottom of the pond where it could either be scooped or vacuumed out, or left to naturally break down slowly into the nitrogen cycle.

I certainly don't have a dedicated koi pond, but this is what would accumulate on the bottom of my pond if I didn't have a bottom drain.

 

[budgenator]

What I personally see as a distinct disadvantage is having a bottom drain (that is not gravity fed), going directly to a pump that purees that waste materials, that would otherwise settle on the bottom of the pond, and blends them up and makes them much harder to capture and remove mechanically

You would think so, but I just rescued 3 fingerlings that made it through my Harbor Freight dirty water pump, through the pipe and around 2 layers of green matula in my filter-falls chamber only to be stopped by the blue matula across the weir! They weren't real frisky when I threw them back into the main pond, but they were definitely alive and not puree. If fish can make it through alive I suspect the puree effect is a "Your Mileage May Vary" deal. I'm going to have to drop the pump and milk crate it sits in now into a laundry bag to keep the fish from getting sucked through.

 

[Mucky_Waters]

You would think so, but I just rescued 3 fingerlings that made it through my Harbor Freight dirty water pump, through the pipe and around 2 layers of green matula in my filter-falls chamber only to be stopped by the blue matula across the weir! They weren't real frisky when I threw them back into the main pond, but they were definitely alive and not puree. If fish can make it through alive I suspect the puree effect is a "Your Mileage May Vary" deal. I'm going to have to drop the pump and milk crate it sits in now into a laundry bag to keep the fish from getting sucked through.

Yeah, it's amazing how tiny fry can sometimes survive the impeller chamber when they are very small. However the key word there is "sometimes". If you really want to test my theory, try catching them and sending them through again ,,, if you dare.
All kidding aside, fish are pretty solid compared to mulm. Usually when fish don't make it through the pump impellers they only come out slightly chewed or only in a couple pieces, but the stuff that settles on the bottom of a pond is about as solid as soap bubbles, it just doesn't come out the same on the other side of a pump.