Can I get away with a 2" Bottom Drain, 5 Gallon Bucket? < 500 Gallon Pond

[Miami Al]

I build my water feature originally to be fountains, and then we decided to add plants and fish. It fell into disarray (like many things this past year) and some plants ripped through the liner, so I'm rebuilding.

Previous build used a bunch of small pumps, to mixed effects. The maintenance on multiple filter boxes and other things resulted in neglect, so this time I plan for simpler. Everything is focused on ease of maintenance first, and the reality of construction.

It's in the front of my house, so to avoid being classified as a pool, it is capped at 18" deep. The frame is about 8' x 3.5'. I'm in South Florida, so it runs year round, no winterizing, and maintenance needs to be infrequent to not dominate my life.

Last time I used a Rhino Retrofit bottom drain, it was massive and some of the plant roots blocked it and that was the end. I was contemplating how to rig it better and decided to see if I can do a bottom drain.

4" is out, it's in too small a part of the yard for it to be viable, beyond to absurd cost and difficulty of working with 4", having room for sweeping 90s (plus the massive size of 4" bottom is absurd.

So I was looking at the Easypro 3 BDA - that looked reasonable for my operation, and running a tube for aeration seemed possible. I have a floating skimmer that provided plenty of aeration last time, but was a bit of a pain to keep cleaning - goal here is simple. The 3" PVC is so hard to work with in this tight area I'm having second thoughts.

Thoughts:
Get a 2" Bottom Drain. 2" PVC is easy to work with, the parts are readily available. Then use a 5 Gallon Bucket with a screw on lid for pre-filter (I can't find anything pre-fab, which I'd prefer). Feed the gravity drain into the 5 Gallon Bucket. Have the pump in there pipe out to a Pressure Filter w/ UV Clarifier built in, then from there I saw a "decorative urn filter" that has a removable top flap for easy of access.

Bucket would be:

Coarse Filter
Medium Filter
Fine Filter
Bio Balls
Pump

Pump would pump to pressure filter for real filtration, which would pass to the urn. I could then plug in the floating skimmer if I want or ditch it.

Plan is to grow one tropical lilly, a bunch of small "fish tank" style plants, and maybe add a few decorate gold fish, guppies, and other decorate aquarium fish.

If the choice is 2" Gravity Bottom Drain + Pre-filter, or 4" Retrofit hooked to an inline pump, which would you recommend? At this time, I am capped at 3 pieces of "always on" electric, but I can at a 4th "later" - right now it's in use for my car.

Which option would be better?

 

[poconojoe]

You absolutely don't need a bottom drain, especially with that small/shallow of a pond.

No need to use such large piping. Way overkill. Match the pipe size to your pump's output. If you feel the need, you can increase it up a size.

If you truly want maintenance free, build a wetland bog filter. It will be the only filter you will need. No pressure filter, no UV lights, no filters to constantly clean out. Period.... Sit back and enjoy a maintenance free pond. Cleaning all those filters gets old real quick.

I have an awful lot of trees but prefer not having a skimmer to constantly clean out or get clogged up. I just use a pool net to catch whatever falls in the water. I'm out there every day and if it needs it, I'll just give it a quick netting. It's up to you if you want a skimmer. Personal preference.

Try to make things simple, not too complicated. More things to maintain or go wrong.

Use schedule 40 flexible pvc where you would normally use a hose.
That corrugated pond hose that they sell won't last very long and it's difficult to attach to those lousy hose barb fittings.
The flex PVC will be the only hose you'll ever have to buy. Plus it mates up to all regular PVC fittings and you use the same primer and glue.

None of my plumbing is outside of the pond/bog. If there's ever a leak, it will not drain my pond/bog.

Use either 45 mil EPDM with the proper underlayment or HDRPE as liner material. Do not use a PVC liner. They are horrible. Too thin, gets brittle from the sun's UV rays and tear easily. I know this from experience.

 

[j.w]

@Miami Al

 

[combatwombat]

I'm with @poconojoe. A bottom drain is not worth the trouble to install on a pond that shallow and small. And 2" PVC on a bottom drain seems pointless. To small—prone to clogging

Suggest skipping the pressure filter and building a bog. If you're having issues w/ stuff settling on the bottom, plumb a few return jets off the line to your waterfall/urn from the pump to keep stuff from settling until your skimmer can get it. Up your skimmer game. Get better surface draw to it.

That should be as close to 0 maintenance as you're going to get.

 

[brokensword]

PJ and CW have it right; you're definitely overthinking what you need, especially for 500 gallons. IF you can, double it and get even more latitude for errors along the way. With a bog type filter, you'll have only the chore of cutting plants back once in a while (after the initial labor outlay).

 

[GBBUDD]

plants ripped through the liner,

what plants went through the liner ?

 

[poconojoe]

what plants went through the liner ?

I was wondering that myself.
Either that is one really invasive plant or a really thin liner.
But, stuff does happen!

 

[Mmathis]

Hello and welcome! Ditto that bottom drain isn’t necessary.

What kind of material was your liner made of that plants were able punch through it? Your liner should be your biggest investment. Get a good, strong liner.

 

[Miami Al]

So my sprinkler pump died, and we didn't notice (it's been a weird year). Everything went dry and some crazy weeds that rampaged through my garden went into the pond and shredded things.

Very invasive plant. When we get angry plants, they get super angry.

Having dug and trenched for the bottom drain, I'll probably install it. Thank you for all the help, it seemed like I was going down a rabbit hole that made no sense. If the 2" drain is an issue for clogging, I'll get teh 3" drain, and just convert to a 2" pipe on the outside of the pond. So I'll run 3" all the way underground, and just connect in... The RTF850 seemed like it should be easy to plumb.

I'm looking at the bog filter now. I thought about increasing it about 50%, the wife said no. The frame and cement coping isn't going anywhere.

My reservation with the bottom filter was cutting into the liner, but I also know that things settled before and I'd like to clean things out. The bog filter seems super intriguing, and could be done in a "whiskey barrel" kind of thing.

I like my skimmer, but it kept popping out of the water without rocks to weigh it down, and rocks were a pain to deal with for cleaning. I'm thinking of replacing the pump on it with one half as powerful, that should simplify a bit.

I feel much better knowing that the challenge with the hose wasn't my personal failings, but rather poor materials.

I hated the box filters, they were gross to clean, and combined with the hose, a nightmare.

I'm rethinking the pressure filter and gravity filter and all of that, maybe I can make a bog filter work.

 

[Miami Al]

So, I spent today contemplating everything, and I realized something: I love the Bog Filter, I just realistically don't think I can get adequate bog filtration set up any time soon.

I also think that if I skip the Bottom Drain, I risk regretting it again.

So, Revised plan 3:

Filter System 1 (Bottom Drain + Urn)
3" Bottom Drain, gravity fed into 7 Gallon Bucket
3" -> 2" Elbow simplifies plumbing
2" Union makes repairs possible
2" Check Valve prevents backflow or prolems
2" Bulkhead connects into bucket
1" Bulkhead creates path out, Urn provides mechanical and bio filtration

Pump pushes water to urn
Air Pump pushes are into air diffuser

Filter System 2 (Bog Filter)

Bog Filter will likely consist of 3 Planters
Center One will be tallest + Elevated 2 inches
Bottom fed in center, two out ports in the center flow to the side planters bottom feeds
Top feeds out of side planters go to Pond Spitters for aeration and visual effect

All connected with 1" Flex PVC

No idea if the spitter plan will work, no idea if the lack of pressure will stop it, or as long as they are lower than the water level in the bog it should work okay.

Thoughts?

I realize it's too complicated, but it seems like a fun project to build.

 

[addy1]

Nice drawing, you have put a lot of thought into your pond.

I don't have a bottom drain, have never missed it. Don't have anything but one external pump and a bog to filter my pond. Have never wanted or wished for anything else. Aeration created by the waterfalls.

 

[Lisak1]

Welcome @Miami Al !

When I read your plans, my head starts throbbing, but I get the idea that you enjoy the planning and engineering, so have at it!

We don't have a bottom drain, never missed it. We've had both big koi in our pond and now mostly goldfish and shubunkins. The idea that you need a bottom drain comes from the world of the Dedicated Koi Pond, where the pond exists just for the fish - no rocks or gravel, no plants. They like to heavily stock the pond and bump up filtration to accommodate the higher bio-load. Your pond is far too small for koi, so you aren't building a DKP, so the bottom drain really is overkill. My biggest concern was always that breach in the liner at the very bottom of th pond - it's definitely do-able, but it does become one more thing to worry about failing.

In the eco-pond world we rely on plants, bacteria, and nature to balance the pond. Keeping the bottom of the pond clean is just not an issue - it happens on it's own.

 

[Miami Al]

Welcome @Miami Al !

When I read your plans, my head starts throbbing, but I get the idea that you enjoy the planning and engineering, so have at it!

We don't have a bottom drain, never missed it. We've had both big koi in our pond and now mostly goldfish and shubunkins. The idea that you need a bottom drain comes from the world of the Dedicated Koi Pond, where the pond exists just for the fish - no rocks or gravel, no plants. They like to heavily stock the pond and bump up filtration to accommodate the higher bio-load. Your pond is far too small for koi, so you aren't building a DKP, so the bottom drain really is overkill. My biggest concern was always that breach in the liner at the very bottom of th pond - it's definitely do-able, but it does become one more thing to worry about failing.

In the eco-pond world we rely on plants, bacteria, and nature to balance the pond. Keeping the bottom of the pond clean is just not an issue - it happens on it's own.

Thank you for the feedback. I'm an engineer by training, that spends most of his time making spreadsheets, so it's fun when I get to build/design things for my hobby.

I filled my pond with plants last time, but didn't know what I was doing.

This was a lot to think about. I am so torn, because the "DKP" world dominates the Internet, so I have so focused on " a bottom drain will solve my problems" - so I'm not sure. Then I read about Bog Filters and I think two things "1 - that makes a lot of sense" and "2 - will Florida's crazy climate trash it."

I figured last time that if I have two separate systems each capable of filtering the pond, I have redundancy. When we had a post hurricane power failure and didn't use a battery pump to aerate it, we lost most of our fish (it was pretty gross). Part of my thought on this is that even if I don't use the aerator on the bottom drain for "DKP" reasons, it's redundancy for Hurricane season.

So I'm going to move away from the silly aquarium company low end stuff (like the pressure filter), the bio-balls, the pump boxes, etc. I will do a layer of pea pebbles below the shelf in the pre-filter for the bottom drain (If I do it), or I may just put a bottom pipe with an output that I can shop vac out from time to time. This was super informative.

Thank you everyone for feedback. If anyone else reads this thread, I'd love more thoughts before I start building. I think I'm going to start on constructing the bog filter and see if I can figure it out.

 

[combatwombat]

I understand how it can become overwhelming and confusing. If you spend much time on koi forums, you will notice there are some unquestionable rules and pieces of equipment that ALL PONDS MUST HAVE to avoid becoming giant cesspools. And then you come to forums like this and find that 90% of of folks don't follow those rules, don't have that equipment and don't seem to have any problems.

Think it's all in the mindset of the two types of pond keepers. Mo' fish = mo' problems and DKP folk really, really like mo' fish. So they have found there are things that must be done to keep a healthy pond in a koi bumper car corral. We don't tend to build ponds to the fish density of Tokyo around here, so you can get away with a lot more relaxed design and care than you can if you were trying to build a clown car for koi.

That said, if you have the ability to design and install a proper bottom drain and don't plan to put rock on the bottom of your pond, you probably won't regret doing it. It will keep the bottom of your bare liner pond cleaner. There's a reason there's a market for retro-fit bottom drains, after all.

You probably just don't need it.

 

[Miami Al]

I understand how it can become overwhelming and confusing. If you spend much time on koi forums, you will notice there are some unquestionable rules and pieces of equipment that ALL PONDS MUST HAVE to avoid becoming giant cesspools. And then you come to forums like this and find that 90% of of folks don't follow those rules, don't have that equipment and don't seem to have any problems.

Think it's all in the mindset of the two types of pond keepers. Mo' fish = mo' problems and DKP folk really, really like mo' fish. So they have found there are things that must be done to keep a healthy pond in a koi bumper car corral. We don't tend to build ponds to the fish density of Tokyo around here, so you can get away with a lot more relaxed design and care than you can if you were trying to build a clown car for koi.

That said, if you have the ability to design and install a proper bottom drain and don't plan to put rock on the bottom of your pond, you probably won't regret doing it. It will keep the bottom of your bare liner pond cleaner. There's a reason there's a market for retro-fit bottom drains, after all.

You probably just don't need it.

Thank you for understanding, 100% true. I am thrilled I found this, because my concept evolved from:
1. Water feature with fountains because I like running water
to
2. Fish, we should add some fish
to
3. Clearly it needs a balanced Ecosystem
to
4. Florida's weeds ate my garden, ack, what to do now

It's funny, I did my last build WITH a retrofit bottom drain, and I was actually cleaning it out to reuse it for this originally. The drawback was, I ran it into pumping in was the Banjo LS200 Y Strainer I used required CONSTANT cleaning. That was why the bucket pre-filter seems so tempting.

Florida's climate is fantastic in that we can be outdoors 365 days a year. It is horrific in that because our system doesn't get a break, it just keeps going. There is no "winter reset" where things die back. There is a "summer explosion" where everything grows.

I thought to keep a clean floor and use a bottom drain just to avoid the over time build up, since I never get a reset.

Is my idea of multiple planters and one feeding the next reasonable for a bog system? I can't really get a single structure the desired size, and I do have an electricity issue if I give two of the three available ports to the bottom drain.

My main takeaway from last efforts:
1. Filter boxes are absolutely disgusting to clean
2. Pond hoses really do suck, and attempting to run splitters made it a nightmare
3. Digging into the pond to clean out more than twice a year is a no-go

I wish I could reasonably retrofit a real skimmer in. I feel if I could bottom drain + skimmer + bog than I think I can tame Florida's climate. The aeration line would really just be a backup for power outages, and I could put it on my switched outlets without risk.

I want to over-engineer it to minimize maintenance and not have a disaster in the future. I figure if all my filtration changes are above ground it becomes like the pool, air conditioners, and whole house water filtration, just another filter to maintain to cover quality of life. I just don't want to have to go digging to deal with filter. I think modern life seems to mostly about filtration