Purchased a Home with an Existing Pond!

[PonderingPerson]

We just purchased a home and in the backyard there is a large circular pond - We were told this was once an in-ground swimming pool that was converted to a pond. The dimensions are 4 -5 feet deep and total diameter is 28ft - an online calculator tells us this is 18,000 gallons!!!

There are approx. 35 goldfish in the pond, 12 new babies they seems to be be doing well. We have only owned the house since winter so now that spring has arrived we are trying to restore the pond, oxygenate and potentially install a filter. The water is currently a thick brownish green color and I can only see 3-4 inches under the surface. We poked around on the bottom and there seems to be a good bit of muck - some gas bubbles emerged as we did this.

There was an existing stone waterfall piped so I recently purchased a high capacity pump to help oxygenate the water. I’m now looking to add some filtration but with such a larger pond my options seem very limited and pricey. The Aqua Ultima II 20000 is one of the few that would be able to handle the 18k gallons but its very costly. Could I run 2 smaller filters instead? Was also wondering if covering the surface 50% full of oxygenating plants hornwort, hyacinth to reduce the sun exposure and clear up some of the algae?

Final question would adding a bottom aeration unit to a mucky pond create a dangerous environment for the existing fish? best to removie them while the aerator clears some of the harmful sulfide.

Thanks for your help!

 

[PonderingPerson]

Posting a pic...

pic!

 

[PonderingPerson]

and another one...

 

[combatwombat]

That is a very cool feature. At 18,000 gallons, I imagine you’d be fine moving about 9,000-12,000 gph.

Removing the muck from the bottom should be a priority, but definitely find a temp home for the fish while you do that.

Bad news on the filter: I’ve never used one of those, but the community consensus is divide whatever the manufacturer says by 2 and you’re closer to reality. So you’d need two of them.

I don’t know what they cost, but if it’s significant, you might as well start looking into building a bog filter. Will work much better and be far less maintenance. Lots of folks here use them and tons of knowledge on how to build.

Also, to prevent future muck issues, you really need an effective skimmer.

 

[combatwombat]

And yes on aeration. I would manually clean muck first and then add aeration.

If you have a smooth bottom, would also be a good time to look into a retrofit bottom drain. You can get one with an air stone attached which will both aerate and improve the effectiveness of the bottom drain.

 

[GBBUDD]

35 goldfish in the pond, 12 new babies

Triple that number if you can only see a couple inches into the water.

I am running a bog filter and just rebuilt my maine filter as i wanted a taller waterfall. and while i was at it make some generational changes that would prevent roots from getting to the aquablocks.

Regardless the only other filter i would ever look at besides a bog is a ProfiDrum ECO 45/40 Rotary Drum Filter (RDF) all your options for that size a pond are not cheap.

A bog at the minimum would require in the neighborhood of 30,000 pounds 1500 bucks in my area CT. of river rock and a containment, a hole in the ground is by far the cheapest way to go. 20 BUCKS BUYS A SHOVEL FOR THOSE ENERGETIC. " I'M NOT ONE I RENT EQUIPMENT" then you need your pump i'd go no less than 12,000 gph 1,000 TO 1500 bucks and liner and thats going to be approximately 1200 oh and you need underlayment and hose so as you see they are all going to run 4 to 5 k .

but if you'd like to see what a bog can do at the bottom of this post is my showcase and my build with all kinds of picture and video's .

welcome aboard

 

[addy1]

Welcome to the forum!

I filter with only a bog, have been doing that for 11 years with this pond, well ponds, I have 10 in a loop all filtered by the bog. From small to large ponds.

 

[Hound Heaven]

What a beautiful feature -- can't wait to see the restoration. You've come to the right place for experienced advice.

 

[rubyduby]

I can't imagine how awesome that pond will be when you clean it out...I don't have a bog (can't in my situation) but would definitely build one if I were you...Can't wait to see pics of the finished product!

 

[PonderingPerson]

Thanks for the knowledgeable replies! Looking into the Bog filter now, lots to learn here. Will definitely keep you updated.

Short term question: Am I causing harm to my fish by running ONLY a pump for now? Since pump is sitting on the bottom am i essentially stirring up all the muck and creating a toxic situation? We just had two 90 degree days and I was thinking I should run the pump to aerate the water and create some surface movement but water looks a little dirtier now I'm concerned I'm doing more harm than good.

 

[combatwombat]

Thanks for the knowledgeable replies! Looking into the Bog filter now, lots to learn here. Will definitely keep you updated.

Short term question: Am I causing harm to my fish by running ONLY a pump for now? Since pump is sitting on the bottom am i essentially stirring up all the muck and creating a toxic situation? We just had two 90 degree days and I was thinking I should run the pump to aerate the water and create some surface movement but water looks a little dirtier now I'm concerned I'm doing more harm than good.

I'm not the most knowledgeable on this, but if you have a lot of muck on the bottom and you're stirring it up, I think you could be harming the fish by releasing a lot of hydrogen sulfide. Recommend raising the pump up off the bottom to achieve circulation without disturbing the muck.

 

[j.w]

@PonderingPerson
You can raise the pump off the bottom by putting a tall pot for it to sit on. That way it won't stir up the muck on the bottom

 

[j.w]

@combatwombat great minds think alike, I posted right when you did

 

[PonderingPerson]

Ahh Perfect! You guys are quick!!! Thanks again

 

[bagsmom]

So - I typically do not gravitate towards anything minimal or contemporary. This pond is the exception! WOW! That is a REALLY cool design. I love it! I can't wait to see what you do with this to get the water quality all fixed up. But the overall look is just perfect. The circle with the simple bridge - that enormous rock - it is fantastic!