Return to the Ponds & Aquatic Plants Forum | Post a Follow-Up

Upgrading filter and water change

Posted by Marcus1017 none (My Page) on
Wed, Dec 4, 13 at 21:59

Hi everyone,

New to the site and wanted some recommendations on what to do. So my pond is 3 years old now realized some mistakes thereafter I built it in which I am trying to correct. Pond is about 5000-5500 gallons. About 24 koi, average size is 8 inches. A few goldfish as well that have multiplied each year. Filtration is the savio skimmer, 6000 gph pump leading to the savio waterfall filter. Skimmer has a 50 watt and a 26 watt UV. The pond is filled with 2-3 inch rocks as the bottom. These last three years, water has always been darkish brown and clearing up in the fall to winter. Right now, it's as clear as I wish it could be all year! So I've realized problem 1: no bottom drain. Problem 2: rocks at the bottom. Problem 3: want to remove the goldfish and leave only koi. Pond is 12 feet by 20 feet averaging 2 1/2 feet in depth. I just bought the aqua II 4000 and a 4800 gph pump for the bottom drain. Questions: should I indeed remove the bottom rocks? I'll also have to drain the pond, I live in New Jersey and was planning on doing this first week of April. Would the water change in the spring stress out the fish too much? Or should I wait until May? And lastly, would adding the new filter be enough filtration? Any assistance would be greatly appricieated. Thank you.

Follow-Up Postings:

RE: Upgrading filter and water change

I would not call myself an expert but I have had good luck with my NJ pond for 9 years now.
It is not as large as yours, about 1500 Gal. and 2.5 ft deep. Same number or more fish and only a skimmer and water fall for filtration. My 1 HP pump does move allot of water by way of a 2 inch pipe to the top of the falls.
A bottom drain may be a good thing but it will be lots of work and I have no problems without one.
Many people will say no rocks in a fish pond. I have large rocks to support the 3 shelves and small river stone on the bottom at about 1.5 inches deep.
If you are truing to address only water clarity I would recommend the following.

1-Remove the rocks on the bottom and replace it with 3/4 river stone or if you like add nothing. This will give the yuck less places to hide. Pond maintenance is important particularly in the spring and fall. Net out all leaves and plant mater as you see it.

2-For brown water, clean the pond, make sure water runoff from the yard cant get into the pond and use gravel around plantings instead of mulch. 10-20 percent water changes from time to time may help too but makes green water worse.

3-Plants plants plants! They are great filters.

RE: Upgrading filter and water change

Mike56 - you have 24+ fish in a 1500 gallon pond? Without extensive mechanical filtration? And the much-maligned rock bottom? Many people would say what you are doing is not possible, as you probably know.

I have a rock bottom pond also - slightly bigger, fewer fish - but people tell me all the time that my rocks are deadly for my fish. In spite of the fact that my fish grow and thrive and swim and even spawn. And my water is clear, no muck on the bottom or anywhere else for that matter. I get in my pond every other week during the gardening season. There's little to no sediment that gets stirred up. We have no mechanical filtration - our only filter is a 6x9 bog - and our "skimmer" is a second waterfall that spills into our underground rain retention where the pump is situated. The water gets pumped back up through the bog. No bottom drain either. Simple, natural pond Eco-system. People look at me funny when I say it, but my pond smells delicious!

So Marcus, take the rocks out if you want. Actually, I think you may have to take the rocks out, if you are set on a bottom drain. But I think you'll find you've got something else going on. Brown water doesn't sound like a lack of filtration. More likely tannin staining from leaves or runoff as mike suggested. I don't know about your fish stress question, but I think the time of year may be less important than where you house them while they are out of the pond.

RE: Upgrading filter and water change

22 fish including (1) 18 inch catfish and( 3) 16 inch Koi. I have never drained and cleaned the pond. I just I add is salt.
The first photo was from 2004. These two photos are from this year with 4 of the fish still happy and alive from 2004 . I lost some of the old fish to birds and raccoons in 2008 and 09.

It works for me but I have never had baby fish. Maybe the big catfish?

RE: Upgrading filter and water change

The try color is one from 2004.

RE: Upgrading filter and water change

Beautiful! Same here - only "water changes" we do is to top off the pond to replace water lost to evaporation. The fish, plants and bacteria all work together to keep things in balance. We attract lots of dragon and damsel flies as well as a good number of frogs and birds. Our pond basically takes care of itself. We keep the plant matter trimmed and scooped to keep things looking near.

Do you ever add bacteria?

RE: Upgrading filter and water change


I did add bacteria each spring for the first few years but I figured out that nature has been taking care of that for thousands of years without any help so I stopped. Maybe its all those nasty stones on the bottom ;-)

I am happy to hear your having good results with a natural echo system pond as well. One thing I learned the hard way in my first 3 years of ponding, is that the more I tried to control things the more problems I made. As to water quality, several of my fish have been badly wounded by an unknown predator and healed quite nicely. I figure if a fish with a large hunk of flesh missing on both sides or the top 3/4 of his tail gone to the bone can heal 100% without ever developing an infection the water must be good.

We just have to wait for spring to get our feet back into the water.

Please post a photo of your pond if you can. I would love to see it.


RE: Upgrading filter and water change

beautiful clear have achieved a clear pond without mechanical
filtration and that's extremely hard to do, you have surly have proven
that it can be done.

We have both mechanical filtration and a 200 gallon biological pond
that services the main pond. Our pond is always clear and healthy.
The bottom drain works well to continually clean the water 24/7...

A pond the size and depth that Marcus has would surly benefit with a bottom
drain. But boy, it would sure be a lot of work now -- since it's all set up already.
....also, all the pebbles/stones would have to be removed permanently as they would
clog the drain. Our koi are big, (18-24 inches long) they dig in the pots
and get the rocks all over the place and we have to scoop them out.

As I mentioned in the other thread, we have a shallow beach with rocks in
it...we have long ago removed the small rocks and replaced them with big rocks
cause the koi would roll the rocks around in their mouths and spit them out
on the pond floor... :( thus, our rockless bottom pond is not always

RE: Upgrading filter and water change

cliff_and_ joann,

Thanks for the comments on my little pond. I have seen photos and maybe a video of your beautiful pond. Its probably the best I have seen. Great fish too.

What do you mean by mechanical filter? I have a filter pad in my skimmer and bio falls. Isn't that mechanical, or is there something else that I don't have?

Always happy to learn something new.


RE: Upgrading filter and water change

Mike, how does the bio falls work? Is there a pump as well as the filter pad
in the skimmer? It's going to sound crazy, but I really only
know how our ponds filtration works...
I am impressed with your water
clarity, many ponders would be envious of the clear and sharp
water you have.
The water goes through your skimmer and pad and you clean
out the filter pad? We just use our skimmer in early spring when the trees
are first budding and we get a lot of floating leaves, then we shut it down.

I'm assuming you have a pump operating the falls, but not a filter box
collecting the gunk?

This post was edited by cliff_and_joann on Sat, Dec 14, 13 at 21:15

RE: Upgrading filter and water change


I have a 1 hp pump located in the skimmer sump with a 2" filter pad below the skimmer basket. This 2" filter gets most of the gunk. From the pump, a 2" hose goes to the bottom of a bio-falls sump and it has two 1" filter pads and a bag of bio-balls. I don't recall the GPM of the pump but it moves a lot of water.

I only clean the falls filters at the end of the season and the one in the skimmer gets cleaned about every 6 weeks. The bacteria in my system do most of the work but I have to keep after the leaves in spring and fall with daily emptying of the basket.

Early spring brings an hair type algae bloom that clears up within about two or three weeks of reinstalling the pump and starting the bio-falls.

Its a standard Aquascaps system.


RE: Upgrading filter and water change

Ah, then there is mechanical filtration. You have proven that you can have rocks and a clear and healthy pond. I always say, there are many ways to
pond, and no one way is the right way.

Our fish love string algae; then devour it, thus we never get to see
string algae. :)

RE: Upgrading filter and water change

Hey guys, just catching up with the thread. I have two ponds, both liner ponds. The first is a 2000 gallon river stone bottom, skimmer to biofalls. I am big into water clarity. I do suggest a pond cleaning every 2 years. Even if your PH and ammonia are good, you should check nitrates and nitrites. I drain the pond and then power wash it with a sump pump at the bottom. My fish I put in a temporary home of a 50 gallon Lowes hard shell pond.
This is for those thinking of bottom drains. My second pond is 46,000 gallon, just recently installed, my dream pond. It has a 6000 gallon upper pond feeding into a 40,000 bottom pond. There are no gravel and bottom drains. My 3 bottom drains and skimmers go to a 4 foot vortex, then split to an Osaka 5 and 6 chamber filter. Honestly guys, taking care if my big pond is easier than taking care of my gravel pond. I love my gravel pond because it looks so natural. Cleaning is a chore, you can't get all the muck. If your looking into a bottom drain, look to run it to an outside filer. Osaka has some great smaller filters. The down side is they are a bit bulky, for instance, my 6 chamber filter is 13 feet long. But you don't need that.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Ponds & Aquatic Plants Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here