Retrofit bottom drains.....

[Mmathis]

I don't have a BD and don't know too much about them.. Tell me about retrofit BD's. How are they installed? What are the requirements for installation, equipment, etc? Do they work well enough to go to the effort?

 

[Mucky_Waters]

You can find way more about bottom drains by Googling them then I could tell you here, but the main advantages of them is that they can gravity feed the sludge on the bottom of your pond to your filter system, without blending it up by going through a pump. By doing this it can be more easily removed. If you plumb a bottom drain, of any sort, through a pump before catching and removing the sludge in some sort of filter mechanism, you defeat the whole advantage of having a bottom drain.
Think of a bottom drain like having a vacuum permanently running in the very bottom of your pond (where the majority of the sludge accumulates).

The biggest problem I have seen with retrofit bottom drains is the way they most often get plumbed, and that is to run the drain line up and over the edge of the pond above the water line. The problem with this is, once any air gets trapped in the pipe above the water line (and it eventually will), it will break the siphon and the gravity feed action of the water will no longer work, and it will be very hard to get the air out because of the large diameter pipe that bottom drains need to be to work properly.
The picture below shows the correct way a retrofit bottom drain should be installed (through a bulkhead),,,and an alternate (wrong) way.

 

[Dave 54]

You can find way more about bottom drains by Googling them then I could tell you here, but the main advantages of them is that they can gravity feed the sludge on the bottom of your pond to your filter system, without blending it up by going through a pump. By doing this it can be more easily removed. If you plumb a bottom drain, of any sort, through a pump before catching and removing the sludge in some sort of filter mechanism, you defeat the whole advantage of having a bottom drain.
Think of a bottom drain like having a vacuum permanently running in the very bottom of your pond (where the majority of the sludge accumulates).

The biggest problem I have seen with retrofit bottom drains is the way they most often get plumbed, and that is to run the drain line up and over the edge of the pond above the water line. The problem with this is, once any air gets trapped in the pipe above the water line (and it eventually will), it will break the siphon and the gravity feed action of the water will no longer work, and it will be very hard to get the air out because of the large diameter pipe that bottom drains need to be to work properly.
The picture below shows the correct way a retrofit bottom drain should be installed (through a bulkhead),,,and an alternate (wrong) way.

I'm a tad confused with the term of bottom drain here Mucky what your diagram shows something as a bottom drain we brits in the koi world are unfamiliar with my friend
A bottom drain to me means exactly that , a drain laid in a trench of sand then connected to the bottom of a linet via a number of rings some silicone and screws as well as the bottom drain itself which is always 4"
The water is then by gravity fed down the pipre which empties out into the vortex , in between the bottom drain and the vortex there should set in the ground be a 4" slide valve to cut the pond off from the filters
First you switch off power to the pump and isolate the vortex from the rest of the filters by shutting the 4" slide, next you drain the vortex by opening the 2" pipe at its base and then shut it.
Then the slide valve is opened and the pond is drained into the vortex again
Shut the 2" valve and open the 4" bottom drain valve to top up vortex again, then when the pond has been topped up again you reconnect the vortex to the filters aain and switch on the pump That in my mind is a bottom drain with 4" slide which is how it should be.
To us that isnt a bottom drain Mucky its a filter connected to a pipe draining into a vortex or do I stand corrected my friend ?


Dave

 

[Mmathis]

I'm a tad confused with the term of bottom drain here Mucky what your diagram shows something as a bottom drain we brits in the koi world are unfamiliar with my friend
A bottom drain to me means exactly that , a drain laid in a trench of sand then connected to the bottom of a linet via a number of rings some silicone and screws as well as the bottom drain itself which is always 4"
The water is then by gravity fed down the pipre which empties out into the vortex , in between the bottom drain and the vortex there should set in the ground be a 4" slide valve to cut the pond off from the filters
First you switch off power to the pump and isolate the vortex from the rest of the filters by shutting the 4" slide, next you drain the vortex by opening the 2" pipe at its base and then shut it.
Then the slide valve is opened and the pond is drained into the vortex again
Shut the 2" valve and open the 4" bottom drain valve to top up vortex again, then when the pond has been topped up again you reconnect the vortex to the filters aain and switch on the pump That in my mind is a bottom drain with 4" slide which is how it should be.
To us that isnt a bottom drain Mucky its a filter connected to a pipe draining into a vortex or do I stand corrected my friend ?


Dave

This is a retrofit BD, if that makes a difference. One added after-the-fact.

 

[Mucky_Waters]

Hey Dave
The diagram shows what they call a "retrofit bottom drain", which is something people usually don't plan to put in, but rather they install after they build there pond (without a bottom drain), and want to install one after the fact without draining their pond and installing it the traditional (proper) way. The idea is that it is still gravity feed and sucks the sludge up off the bottom of the pond. Never having used or installed a retrofit bottom drain, I don't know if they are just as effective as a properly installed bottom drain, I imaging if plumbed in with the bulkhead method they would be nearly as effective, but as you can imagine, that over the top of the liner method of plumbing would be fairly problematic.
As for your claimed exclusive use of 4" pipe in the UK, well, here in North America 3" is pretty common, especially in smaller ponds with lower flow rates. Probably anything under 4000 gal could get away, or even work better with a 3" since you'd have to have to have too much flow in a smaller pond to get a 4" drain work properly.

I'm a tad confused with the term of bottom drain here Mucky what your diagram shows something as a bottom drain we brits in the koi world are unfamiliar with my friend To us that isnt a bottom drain Mucky its a filter connected to a pipe draining into a vortex or do I stand corrected my friend ?


Dave

Gravity feed to the filter is the key, whether that filter be a vortex tank, sieve, settling chamber, or whatever.
I hope you are less confused now.

 

[Mmathis]

You can find way more about bottom drains by Googling them then I could tell you here, but the main advantages of them is that they can gravity feed the sludge on the bottom of your pond to your filter system, without blending it up by going through a pump. By doing this it can be more easily removed. If you plumb a bottom drain, of any sort, through a pump before catching and removing the sludge in some sort of filter mechanism, you defeat the whole advantage of having a bottom drain.
Think of a bottom drain like having a vacuum permanently running in the very bottom of your pond (where the majority of the sludge accumulates).

The biggest problem I have seen with retrofit bottom drains is the way they most often get plumbed, and that is to run the drain line up and over the edge of the pond above the water line. The problem with this is, once any air gets trapped in the pipe above the water line (and it eventually will), it will break the siphon and the gravity feed action of the water will no longer work, and it will be very hard to get the air out because of the large diameter pipe that bottom drains need to be to work properly.
The picture below shows the correct way a retrofit bottom drain should be installed (through a bulkhead),,,and an alternate (wrong) way.

OK, I can tell enough just from looking at the set-up that having a BD (retrofit or original-build) isn't something I'm ready for at this point in time. It's definitely an aspect of the pond-build that needs to be planned for in the beginning stages, taking into consideration your space and pond-educational level (LOL!).

Maybe, if we ever move to another home........we've already decided that our NEXT pond is going to be done by professionals -- or at least, by hiring someone who knows the RIGHT way to do things.

 

[Dave 54]

OK, I can tell enough just from looking at the set-up that having a BD (retrofit or original-build) isn't something I'm ready for at this point in time. It's definitely an aspect of the pond-build that needs to be planned for in the beginning stages, taking into consideration your space and pond-educational level (LOL!).

Maybe, if we ever move to another home........we've already decided that our NEXT pond is going to be done by professionals -- or at least, by hiring someone who knows the RIGHT way to do things.

Why pay for professionals its a pretty straight forwards thing to do you drop your trench in the bottom of the hole you plan to put your pond in then connect the two up jobs a good one an everybody is happy especially your bank manager


Dave

 

[Mmathis]

Why pay for professionals its a pretty straight forwards thing to do you drop your trench in the bottom of the hole you plan to put your pond in then connect the two up jobs a good one an everybody is happy especially your bank manager


Dave

Oh, Dave! I didn't even do a very good job on the pond I have now....

 

[JohnHuff]

If I were to completely do a new pond, I'd probably add a retrofit bottom drain to it. Not a real bottom drain since I don't really want a hole or pipes under, but one of these retrofit ones. Right now, my pond is too full of plants and stuff to put one in.

 

[Mucky_Waters]

Hey TurtleMommy
everybody has their own idea of what the right way to do things is. My right way probably doesn't totally agree with somebody else's "right way", but that doesn't stop me, or that person, from calling his or her way the "right way". LOL
The main advantage of a bottom drain system is easier cleaning of the pond, and a more self cleaning pond. You just have to look at how most swimming pools are designed. They have skimmers, tangential returns (TRPs), and bottom drains. These are all designed to be help the swimming pool clean it self with the normal circulation of the pond. Even with those things swimming pools still get dirty and need regular manual cleaning, but you can imagine how much dirtier a swimming pool could get if it didn't have skimmers or a bottom drain.
Ponds are a little different, especially water garden type ponds where we are willing to accept, or even encourage, a certain amount of dirt since we need it to create a friendly environment for nitrifying aerobic bacteria. The problem is if we have too much dirt build up you can get anaerobic bacteria growth, and you really don't want too much of that in your pond if you can help it. You'll find that bottom drain systems are more of a standard practice for people who exclusively keep quality koi, and want their ponds to be a clean as possible to reduce the chance of diseases or parasites from infesting their fish. I don't have any expensive koi, but I do find my bottom drain filter system much easier to maintain then the box or pump in the pond type of system. Been there, done that.
On the other hand, a lot of people are perfectly content to manually clean out their ponds, with nets or vacuums and such, when they feel it is required, and for a typical back yard water garden where a high degree of cleanliness isn't really necessary, there's probably no need to get any more complicated. Not that a bottom drain is all that complicated, in some respects it's actually less complicated, when it comes to ongoing cleaning. Dave mentioned how easy it is to clean out his settling tank by opening and closing certain valves and just letting the mucky water drain out of the vortex chamber , I do mine a little different, I don't bother to shut down the pumps or isolate the settling tank, I just open the drain on my settling tank and drain the muck into a bucket and pour it in to the garden and rinse off a top screen. That cleans up 90 % of the muck. I do have a quilt batting fines filter I often run too and it takes a while to wash out the batting, but lately I've just been replacing the batting. Getting lazy I guess.

Once you build a pond and start maintaining it, it's easy to see ways to improve on it. I've got a few things I would have done differently on my pond, but I'm glad I put a bottom drain system in this time.

 

[crsublette]

I don't have a BD and don't know too much about them.. Tell me about retrofit BD's. How are they installed? What are the requirements for installation, equipment, etc? Do they work well enough to go to the effort?

Yep, Mr. Muckywater did very well there. There is nothing too fancy nor as technical about them when compared to installing an original bottom drain.

Only thing to think about is the water flow through the pipe. In the thread, bottom drain, plumbing and pump advise needed, I talk and provide many references about bottom drains. The functionality of a retrofit BD is no different than an original BD.

The only difference between a retrofit BD and an original BD is that one sits on the pond floor and the other is more flush with the pond floor.

However, since the retrofit BD is not flush with the pond floor, then there will be obstructions created due to the pipe so there will be debris build up, but this can be easily fixed if you just DIY a PVC wand so to disturb the debris away from the crevices.

Post #6 in the mechanical filtration choices discussion thread explains how I did my retrofit BD, but I was able to do this since I use suction side, pressurized filtration.


The most important thing to think about with these retrofit BDs... What type of flow rate do you want out of it?

 

[RobAmy]

Honestly I do not see why you would retrofit one, just use a pond vac when needed. If you build new then add bd drains then if wanted.

 

[Mmathis]

Well, that's sorta w

Honestly I do not see why you would retrofit one, just use a pond vac when needed. If you build new then add bd drains then if wanted.

Yep, that's kinda what I'm thinking now, after reading some of the other posts. Think I commented on that somewhere. My DIY skills aren't that successful, LOL!

 

[Dave 54]

Yep, Mr. Muckywater did very well there. There is nothing too fancy nor as technical about them when compared to installing an original bottom drain.

Only thing to think about is the water flow through the pipe. In the thread, bottom drain, plumbing and pump advise needed, I talk and provide many references about bottom drains. The functionality of a retrofit BD is no different than an original BD.

The only difference between a retrofit BD and an original BD is that one sits on the pond floor and the other is more flush with the pond floor.

However, since the retrofit BD is not flush with the pond floor, then there will be obstructions created due to the pipe so there will be debris build up, but this can be easily fixed if you just DIY a PVC wand so to disturb the debris away from the crevices.

Post #6 in the mechanical filtration choices discussion thread explains how I did my retrofit BD, but I was able to do this since I use suction side, pressurized filtration.


The most important thing to think about with these retrofit BDs... What type of flow rate do you want out of it?

You touched on an important question there Charles just what diference would you get in flow between a reto fitted and a purpose built bottom drain , I'd hazzard a guess that the retorofitted is slower than the normal bottom drain.
Mucky noted the ease of cleaning I get with our own layout , I honestly thought this is what fish keeping was all about the ease of maintenance which is if you remember why we left our large indoor koi tank for the pond,
During maintenance each week I think I acctually spend around 10 minutes being busy with light duties the next three hours sat by it in summer and in winter sat in the house , even the cleaning of the rest of the filters takes less than half an hour bu from what I've learned from this site its not the ordered world of the koi but the wacky world of fishkeeping and I mean that in the nicest of terms

Dave

 

[crsublette]

Not for sure why the retro fitted BD would have a slower flow rate. A height difference of half inch (12mm) or slightly more in due to installment would not have crated much head height to have an impact on the flow rate.