Bulkhead fitting for pond liner? Please help!!!

[carolinaguy]

contrary to the general consensus, there are folks on this website who use bottom drains and external pumps and have no problems with them. personally i wouldn't use a submersible as my main pump because of the durability problem and the potential for a short.

as for your bottom drain, if the pond depth is at 3 feet, you should use one of the standard bottom drains manufactured by companies like tetra. the bulwark fitting you have pictured is okay but will not resist the pressure as well. our tetra drains have six stainless steel screws to create the pressure needed to seal an opening in the liner at depth.

the secret to an epdm liner penetration is a brand new knife blade coupled with patience. you want the opening to be slightly smaller than the fitting for a snug fit and no rough edges in the hole that will promote tearing. you won't need a sealant. the drain clamps down with enough pressure to counter water pressure. these bottom drains also have covers to keep smaller fish out of the intake tube. i've even read where the cover prevents a super strong pump from sucking the guts out of a fish that gets too close, but those pumps are in the 10000 gph level or higher.

anyway bottom drains provide several important functions and should be in the plan for any pond. you are doing a good thing by adding one.

 

[Pondmaster]

Would you please expound on the so called durability problems and the electrical shorts.

 

[DrDave]

I have used submersible pumps for 42 years without a single incident. You clearly are grasping at straws and have no real experience with them.

I enter my ponds all the time and have no fear of electrucution because it is imposssible.

I can stand next to my pond at night when it is very quiet and not hear any of the 4 pumps running. Try that with any external pump.

Who wants to hear a pump running where you want peace and tranquility?

 

[ponderpaul]

I just finished a rework of my pond – new liner, etc. At 71 I didn’t want even the remote possibility of something leaking because I pierced the liner for any reason.
My “bottom drain” is a joint of 3” PVC beveled on the lower end to sit close to the bottom –not just an open pipe. It gravity feeds into a diy filter/pump box. Seems to be working well, picks up a lot of stuff in the filter. The pipe is painted black so as not to be highly visible. Best of all, when I lose a little water, I don’t have to wonder if I have a leak that I can’t visibly inspect around a hole I cut into my liner.
To each his own – whatever works for you, use it and enjoy your pond!:arrow:

 

[addy1]

LMAO our bottom drain is going to be pvc also......... slotted and T'd

Will not ever put in a liner cut bottom drain, also at point in life do not want to look for that leak in the bottom.

 

[carolinaguy]

Would you please expound on the so called durability problems and the electrical shorts.

be glad to, and this is not heresay. you can glean the same information by researching submersible pumps and external pumps online. the information is also included in several koi books considered to be reputable and well written.

a submersible pump operating life is estimated at one to three years of continuous operation before failure. some folks have used them for up to five years of continuous operation successfully. they typically leak and short causing electrocution in pond fish, a common problem that is responsible for many of crooked spine koi that have spinal damage from electrocution.

external pumps can last for as long as 15 years without problems. one of my club members has an external he has used for that long without an issue. given that these pumps don't require seals to keep water out and are usually manufactured for much more powerful water flows, they are exceedingly durable. my main pump is a sequence built to pump 6100 gallons per hour and is three times the size and weight of a submersible equivalent. it also has an attached pot strainer that screens waste before entering the pump to prevent rocks and debris from fouling the impeller. it has a sealed cover that i can remove to take out screened debris.

bottom line, you just get more and easier with an external pump.

 

[koiguy1969]

my tetrapond 1200 gph pump is going into in its 8th year trouble free.....all my tetra ponds are past 3 years!!!
My 1000 gph tetrapond runs 24 / 7 / 365 for years ...i guess mine are exceptions to the rule, then!!
they are all SUBMERSABLES!!

 

[Pondmaster]

be glad to, and this is not heresay. you can glean the same information by researching submersible pumps and external pumps online. the information is also included in several koi books considered to be reputable and well written.

a submersible pump operating life is estimated at one to three years of continuous operation before failure. some folks have used them for up to five years of continuous operation successfully. they typically leak and short causing electrocution in pond fish, a common problem that is responsible for many of crooked spine koi that have spinal damage from electrocution.

external pumps can last for as long as 15 years without problems. one of my club members has an external he has used for that long without an issue. given that these pumps don't require seals to keep water out and are usually manufactured for much more powerful water flows, they are exceedingly durable. my main pump is a sequence built to pump 6100 gallons per hour and is three times the size and weight of a submersible equivalent. it also has an attached pot strainer that screens waste before entering the pump to prevent rocks and debris from fouling the impeller. it has a sealed cover that i can remove to take out screened debris.

bottom line, you just get more and easier with an external pump.

"Well, there you go again"

On the magnetic drive pumps all electrical components are completely sealed in a non-toxic plastic resin. The impeller is mounted on a magnet that is chased around in circles by the electrical charge from the sealed motor. They are safe and efficient, the companies that produce these submersibles have been in buniness for decades. You apparently have been reading old outdated literature.

 

[carolinaguy]

"Well, there you go again"

On the magnetic drive pumps all electrical components are completely sealed in a non-toxic plastic resin. The impeller is mounted on a magnet that is chased around in circles by the electrical charge from the sealed motor. They are safe and efficient, the companies that produce these submersibles have been in buniness for decades. You apparently have been reading old outdated literature.

the phrase "oh well there you go again" harkens back to ronald reagan's famous response in his political debate against president carter. that was a political debate where impressions are more important than facts. this is not a political debate, and i frankly don't care which pump anyone uses. i've got two submersibles that i use occasionally in my pond, and they work well. the simple fact is that, in an engineering problem, simpler is better, and if the problem eliminates the need to maintain seals around a pump, the solution is less complicated. i'm not using old information, and you can go out there and find it for yourself. if you have submersibles that last longer than the norm, great. my hat is off to you. at the end of the day, whatever works is best. i just take exception to the idea that externals are not a valid choice and submersibles are the only answer. there is another simple response "never say never". i've visited almost a hundred ponds and a dozen koi farms. the guys, you excepted, who have been around a long time and have serious experience in pond construction use externals and swear by them over submersibles. that's an undeniable fact. i've never seen a submersible in a koi farm or at the site of a major vendor. we also have members in our club who use submersibles and choose them over externals. that's great. i just don't believe one category is better in all circumstances for all people. that's all.

 

[DrDave]

You can't compare the peace and tranquility of a backyard pond to a large commercial koi business.
Commercial Koi ponds have a need for extremley large volumes of water and they don't care about the cost or noise, that is just part of doing business. They also don't care that the ugly, noisy pump is visible and often in the way of a natural setting.
I watched a show on Discovery over the weekend, you can probably Google Dr Electric and find him. This man stood in his swimming pool with 500,000 volts from a Tesla coil arching into his metal glove and going through the water to the ground return to the Tesla system.
I wonder how a fish can complete an electrical circuit by being in the water? Fact is they cannot unless they grow hands and grab both ends of the electrical path to complete the circuit.
A lot of these articles are mere speculation as to what happened to cause the spinal twisting. I have had Koi, raised in aquarium tanks develope this condition. I'm not convinced an electrical short can cause this.
Many experts contribute this condition to malathion that has found it's way into the water. That I can believe and most everyone uses it or has a neighbor that sprays it once in a while. Pest control uses helecopters to spray entire communities with malathion for mosquito control.
No-one is saying external pumps are bad, just expensive, noisy, ugly and hard to repair if one goes out you may not get it fixed before your fish die. I can swap out my submersible in 1 minute flat.

 

[carolinaguy]

no argument with the idea that spinal distortions may be the result of other insults like chemical contamination. i saw a fish about 4 weeks ago at a member's pond that developed a deformed spine overnight without any possibility of a stray electrical charge. there is also a nutritional factor that can play a role. agreed.

i've got an external built right into my pond design, and you probably couldn't find it without a hint. externals demand more thorough designs to maintain harmony and aesthetics, but it's easy to do,

and i'll accept your swap out challenge just for the fun of it. my design takes about the same amount of time to install my backup pump. we use the removable gasket fittings from lowes and i pre-installed them so both pumps fit the same space. mine probably takes a couple of minutes though.

whatever works.

 

[DrDave]

A healthy, civil argument is always welcome here. While some of us oldtimers are set in our ways, there is always something to be learned.
Coming from a Reseach background, I like to trust but verify, just like Ronnie...

 

[mrtank]

Welcome to the forum. What part of texas are you in? We have lots of Lone Stars here.

Burnet Tx is the corporate office we're at, bout hr. outside of austin..

we have drop ship locations nationwide..

 

[DrDave]

I hope you are here to contribute to the forum and not just sell. Most new folks start by going to the Introduction thread and telling us about their ponds and interests first.

 

[DrCase]

i've got an external built right into my pond design, and you probably couldn't find it without a hint. externals demand more thorough designs to maintain harmony and aesthetics, but it's easy to do,

and i'll accept your swap out challenge just for the fun of it. my design takes about the same amount of time to install my backup pump. we use the removable gasket fittings from lowes and i pre-installed them so both pumps fit the same space. mine probably takes a couple of minutes though.

whatever works.

Good planing and working the problems out before you start puts you way ahead
with pumps and filters ...Gotta agree totally

I have had 2 fish that were bent i felt it was just the way the egg got rolled