15 replies to this topic

[Ponderthis]

Hello,

I just joined this forum after stumbling across it last night and not being able to leave the site until 5 hours later. I love what y'all are doing with the DIY stuff, and have a couple of probably dumb questions to ask.

First, let me tell you that a few months ago, on a whim, I decided to build a pond in my side lot. It's under a vine covered Gazebo and we basically dug a hole in the ground, put a liner in it, filled it with water and threw in a pump that would circulate the water every 2 hours or so. It's approximately 1,300 gallons and besides the Heron that ate all of our fish a few weeks ago, was doing very good.

Since I am now fishless, I would like to rebuild the pond with cinder block sides and make it about 3,500 gallons or so.

Finally my first question - I have been looking at the 55 gallon filters y'all are DIY'in and was wondering, do these serve as both a biological filter as well as a mechanical filter? Should one 55 gallon filter like this be the only filter I will need to keep my pond clean and clear?

I'm sure I will have some more Q's, but figured I'd start with the one that will help keep my water clear and be as low-cost as possible.

[DrDave]

Welcome to the Forum.
Go to my site in the signature below and you will see how my 55 gallon "Doc Filter" was built.

[Ponderthis]

Yeah I already checked it out, and will again. But I was wondering if just one 55 gallon filter would work as the only filter for a 3,500 gallon pond?

[koiguy1969]

i think i'd go with 2 barrels for 3500 gals...what kind of fish load are you looking to have?

[DrDave]

That depends on your fish load.

Ponderthis said:

Yeah I already checked it out, and will again. But I was wondering if just one 55 gallon filter would work as the only filter for a 3,500 gallon pond?

[Ponderthis]

Apparently like most Koi lovers, I want as many as I can safely fit into a 3,500 gallon pond and not have to spend every hour I'm not at work cleaning it. According to a website that I had run across somewhere that had a calculator for how many inches of Koi you can fit per gallon of water, it said I should be able to maintain a clean pond with approximately 20 Koi at 3,500 gallons.

Finding the money to buy 20 Koi will be the next bridge to cross but I could always buy them pretty small and watch em grow I guess.

[DrCase]

Small ones grow fast its a good way to get started
I would use 2 drums on your pond

[DoDad]

How many inches did you figure for each koi when doing your calculations?

Ponderthis said:

Apparently like most Koi lovers, I want as many as I can safely fit into a 3,500 gallon pond and not have to spend every hour I'm not at work cleaning it. According to a website that I had run across somewhere that had a calculator for how many inches of Koi you can fit per gallon of water, it said I should be able to maintain a clean pond with approximately 20 Koi at 3,500 gallons.

Finding the money to buy 20 Koi will be the next bridge to cross but I could always buy them pretty small and watch em grow I guess.

[DoDad]

Koi for 3500 gallons I calculate you should go with 7.

[DoDad]

That was figuring the koi at 20".

DoDad said:

Koi for 3500 gallons I calculate you should go with 7.

[Ponderthis]

I don't remember what site I went to but it calculated that I could have roughly 300 inches of fish on 3,500 gallons. I just visited a couple more sites that calculated more like 140 inches, which would make the 7 fish at 20 inches correct. But since I won't be starting with 20 inch fish (cuz they cost way too much), I think I'll still go with 20 or so and figure out what to do with them when they grow too big for that many to be in the pond. Probably make the pond bigger, lol...

I think I will go with two 55 gallon drums as suggested then. My only question now is, if I go with 2 drums, can I start with a 1" inlet into the first drum, then have it flow into the second drum just like it does the first drum with a 1" inlet and then use like a 3" outlet to feed the waterfall? Or do I need to go with a 2" inlet into the second drum?

Thanks for all of the help so far.

[DrDave]

Make all your gravity fed outlets 2" or more for a 1" inlet under pressure. I had a 3/4" inlet and a 1 1/4" outlet and that did not work well. I had to choke down the pressure.
Now I have a 2" outlet and it is perfect for the 3/4" inlet.

[DrCase]

Dito DrDave 2" on any thing comming out of the filter
Like DoDad said on the fish load , you do have a max on mature fish..start small and weed them out

[Ponderthis]

Thanks. I have been surfing the web for pumps and thought I had the one that would work picked out. But before I go ahead and buy it:

The first 55 gallon drum will be about 10' from the pump. I will be going up approximately 4' to get out of the pond and I'm estimating the height to go into the top of the drum is roughly 3'. Add another 2' for estimation errors that would give me a head height of approximately 10.5 if I did my calculations correctly and use flex pipe instead of PVC pipe.

One of the pumps I was considering is the Tetra Debris Handling Pump DHP-4200, which has max flow of 4,235 gph and handles debris up to 1/4".

Any thoughts?

[Bullfrog]

I have a link to a very detailed biofilter build with a lot of pictures but can't post it yet. You must have 5 or more posts to include a link or a picture. I'll put it up later. As JW and Freddie Peepers know, I am a man of few words, I have a few words about everything.