1. Missed the live Ask the Expert event?
    Catch up on the conversation about fertilization strategies for success with the experts at Koch Turf & Ornamental in the Fertilizer Application forum.

    Dismiss Notice

Pond Bottom Drains

Discussion in 'Water Features' started by jd boy, Mar 16, 2005.

  1. jd boy

    jd boy LawnSite Member
    from nw ohio
    Messages: 173

    I've Installed over 100 ponds, but have never used a bottom drain. I like the notion, but I am fearful of that seal leaking. Also, it seems that they would be better suited for a koi or liner pond. I like to build more the aquascape natural look with rocks & gravel.

    1. What are your thoughts on them in general?
    2. Do they accomplish anything with a gravel bottom?
    3. Does the bulkhead fitting around the drain truly form an easy water tight seal?
  2. Victor

    Victor LawnSite Bronze Member
    Messages: 1,430

    Hey I was wondering if you'd mind if I called you BOY? I'm just kidding you JD. :p

    To answer your questions, I'll take them in order.

    "1. What are your thoughts on them in general?"

    What I think about them would depend on the intended use of the pond JD. In a koi pond, I think bottom drains are priceless. In a water garden, they can be useful, but I don't think I'd bother installing them. They could still be useful in such a pond though.

    To name some of the reasons why they are so useful in certain applications...

    1. They greatly reduce maintenance. Bottom drains greatly reduce maintenance, because when bottom drains have the proper amount of water flowing through them, they act like continuously flushing toilets (flushing and sucking waste off the bottom of a pond. In a pond, common sense tells us that any debris that gets into a pond, will normally end up on the pond's floor. If that pond has a bottom drain, or drains, the drains (if the pond is properly set up) will remove the debris from the pond. The debris that gets sucked into the drains will be sent to a filter, or sump, where it will be very easily removed and disposed of. If you don't have bottom drains in your pond, the debris that makes it to the pond floor will have to be removed by more difficult means. In a smaller gold fish pond, this might not be a big deal. To clean the floor of a 2 foot deep gold fish pond, you can put on waders and walk anywhere you want to go in the pond, so you can suck up debris off the pond's floor. You can do this without draining down the pond. Most ponds like this won't build up an appreciable amount of debris anyway unless it blows into the pond, since goldfish don't create much in the way of waste. If you have a large, deep (6 1/2 feet deep) koi pond like mine, you can't just throw on a pair of waders and head out into the pond. Well I could, but I'm not going to use my scuba gear to clean my pond. I'll let my bottom drains take care of the cleaning duties for me. I love the fact that while I'm doing other things, they're always at work (keeping the floor of my pond clean). When I'm in bed at night, they're out there working. With that said. If you're going to install bottom drains in a pond, you need to set your pond up so that your drains will be as effective as possible. You will diminish their effectiveness greatly by not incorporating certain design qualities into your pond. If you're going to use bottom drains on a pond, one of the biggest mistakes you can make would be to cover the bottom of the pond with gravel. DO NOT COVER THE FLOOR OF A BOTTOM DRAIN POND WITH GRAVEL! :nono: Gravel will greatly limit the drain's ability to draw debris toward it's mouth. If you're going to use drains, you'll also want to make the pond floor into a bowl shape. This will help direct any debris into the draw-zone of the drains. You will also want to make sure each drain you install has the proper amount of water flowing through it. Every bottom drain is designed with a particular flow-rate in mind. When you select your drain(s), be sure to find out how much water is supposed to flow through the drain(s) per unit time (the instructions for the drain should tell you this). If you can't find a flow recommendation, you can contact the manufacturer to find out.

    It will be much easier to answer your second question JD.

    "2. Do they accomplish anything with a gravel bottom?"

    In most gravel bottom ponds, they won't accomplish much. The gravel will tend to trap most debris. Sorry for the long answer to this question.

    Your last question was...

    "3. Does the bulkhead fitting around the drain truly form an easy water tight seal?"

    As long as you take your time and make sure that all of the mating surfaces are clean, a durable, watertight seal should result. It is highly recommended that you use silicone sealant to help guarantee a watertight seal. WHEN I SAY TO USE SILICONE SEALANT, I'M NOT TELLING YOU TO GO DOWN TO YOUR LOCAL AUTO PARTS STORE TO GET IT EITHER! Only use aquarium safe silicone sealant on your bottom drains! I wish I could say that no one has ever made the mistake of using the wrong kind of sealant. :dizzy: Once the drain has been installed, I'd recommend at least a 2 day curing time for the sealant.

    I hope this helped you buddy. Now........ Do you want to know my opinion on politics? :laugh:

  3. Victor

    Victor LawnSite Bronze Member
    Messages: 1,430

    Another thing about bottom drains and setting them up right... Most well- designed bottom drains will allow you to adjust the height of their domes. In other words, you'll be able to adjust how much distance will be between the lip of the dome and the pond floor. Getting this adjustment set right is important. You can increase, or decrease the draw-zone of a drain by adjusting the dome-height so that it sits higher, you'll decrease the draw-zone of that dome (the draw-zone refers to the distance a particle of debris can be from a bottom drain and still be pulled into the drain by the water going into the drain). If you adjust the dome, so that it sits lower, you will effectively increase the draw-zone (the bottom drain will effectively draw debris into it, from further away). A consideration that you should know is that it's possible to have too much draw and it's also possible to have too little. If you have too much draw, your fish won't be able to comfortably rest on the bottom. They'll have to fight to keep from being sucked against the drain, or even worse (into the drain, if they're small enough). If you don't have enough draw, your drains will wind up being pretty ineffective. At that point, it's almost a moot point that you have bottom drains installed at all. Depending on the pumps thats are installed (i.e. their flow rate), the proper dome height can change, but I normally recommend setting dome heights at 1".

  4. Victor

    Victor LawnSite Bronze Member
    Messages: 1,430

    If you install bottom drains in a customer's pond. Tell them to make sure they flush the pipes that lead to the drains once in a while. All drain pipes collect silt and other debris over time. Flushing the drain's pipes will clean that stuff out of there.

  5. Critical Care

    Critical Care LawnSite Bronze Member
    Messages: 1,654

    Just like the bottom drain, the skimmer box could have a problem with leaks, but that shouldn't keep you from installing one. I suppose the most secure pond would be one where all the plumbing is external, no holes punched through the liner, no rocks that could cause problems too.

    I have a knife valve in line with the bottom drain of my own system where I can regulate the amount of water being drawn in from the bottom. It's a nice option being able to choose how much water you want skimmed off of the top, and how much off of the bottom. During heavy winds with lots of pine needles falling into my pond I'll often close off the bottom drain just so I get all skimming action.

    Victor, I'm wondering how your flushing out your bottom drain lines? Backflushing it by routing a pump to the bottom drain's outlet? I've never done this, but may try it sometime just to see what happens. Could blow my koi out of my pond, eh?
  6. Victor

    Victor LawnSite Bronze Member
    Messages: 1,430

    All you have to do is

    1. Turn off the pump that is supplied by your bottom drain, or drains. After the pump has been shut down, close the valve that will isolate your sump, vortex chamber, or filter from the pump (or wherever your drain pipes empty into).

    2. Next, you're going to want to close the valve between your sump, vortex chamber, or filter from the bottom drain.

    3. Now is when you will need to drain the water out of your sump, vortex chamber, or filter.

    4. When you've drained this water out, you can then flush your drain pipes by fully opening the valve that's between your sump, vortex chamber, or filter and the bottom drain. The sudden rush of water flowing through the drain pipe, will flush silt, or debris that's settled in your pipes out into your sump, vortex chamber, or filter.

    5. Empty the flushed water/debris out and repeat until the water you flush through your pipes is clean. If you have more than on bottom drain like I do, you'll want to only flush one drain pipe at a time.

    6. Open all of the valves you closed.

    7. Top off your pond with dechlorinated water and you're ready to turn your pump back on.
  7. jd boy

    jd boy LawnSite Member
    from nw ohio
    Messages: 173

    thanks guys. victor you answered my question when you said don't use drains with a gravel bottom. I figured they would not do much in that circumstance but it was worth a shot.

    I guess I will have to sacrifice and do some cleaning myself because i'm not willing to give up on the natural water garden look.

Share This Page