How to build a bio filter

[gardenlady]

I still consider myself a newbie even though I've had a pond for a few years. People here have been very helpful in the past so wanted to see what information I could get in regards to building a bio filter. My pond is doing exceptionally well but I do have suspended algae making it difficult to see my fish unless they get close to the surface. It's was crystal clear until we starting getting our Houston heat. I did do a 30% water change which made it better that day but now it's back to where it was. In doing research on suspended algae there seems to be a lot of ideas in building a bio filter to get rid of it. There are so many ideas I thought I would come here and see what the pros suggest. The pond is about 2,500 - 3,000 gallons and is about 4-5 feet deep and I do have a number of plants but have added more just recently. I don't really have room aesthetically to put something outside of the pond so am leaning towards having it setup in the pond. I've used the batting for quite some time now to keep the water clear but this is the first time I've dealt with this type of algae. I've up to to two areas with the batting but it's not really helping to clear it up which is why I thought perhaps we need to do the bio filter. Any information is greatly appreciated.

 

[MitchM]

A bio filter is a general term for providing increased surface area with good water circulation in a container built for that purpose and can be a combination of mechanical filtration that you clean regularly and something with a lot of surface area, like bio balls.
Can you describe what you have for water circulation now and maybe post a couple of pictures of your pond and present filtration set up?
Also, have you performed any water tests, and can you post the numbers if you have?
What do you have for fish?

 

[gardenlady]

We have the waterfall and two spitters but the spitters are spitting in to baskets full of batting at the moment. The pump is a 3200 GPH. I have koi and japanese fantails, shubunkins and a shark *carp*. Probably about 8 koi all very small except one that might be 6-8" making a total number of fish ata about 20. I've been testing the water everyday and the numbers are as follows and they are my normal numbers except for the ph lately which has been better. Ammonia has always been zero, same for nitrite and nitrate. My PH normally is always a royal blue but it's consistently that color and it's the same if I test my tap water. After doing a 30% water change the meter reflected a 8.2 and I did the test tube test just to see if it came out the same and it did. This was early in the morning. Last night is was 9.2. I just calibrated it and it reflected an 8.8. My KH normally took anywhere from 16 -18 drops to turn yellow but recently I've been pleasantly surprised to see it taking 11 -13 drops. I feel like all of this is great. I also try to keep the pond salted and at about 0.1 but it's been raining a ton here and it's dropped to 0.05 but I haven't had a chance to mix the pond water with the salt to raise it up. Thanks for taking the time to respond! I need to add a photo of the pond from my desktop compouter so will post this and add a pic as quickly as possible.

 

[gardenlady]

Photo fo pond

 

[MitchM]

Beautiful pond.
I can see why you don't want to add anything outside of it for filtration.
The most likely location for a filter then would be in your waterfall.
Something like this:

or this:

Unless someone has a better idea.

 

[gardenlady]

So exactly how big is that, where exactly would that go ..at the bottom of the waterfall or in the water at the bottom, and I should be able to make this or can you purchase it? From what I read you're supposed to just leave these things alone to do their thing and maybe clean them once every year or two and also saw a post about adding benefical bateria to get it started and other places that never mentioned it at all. Another question is if it is advisable to add more areation to the pond because of the heat? I have found about three dead fish in the past three months when I walk out in the morning. None of them spend any time at the top of the pond gasping for air but still wondering since my tests are all good.

 

[MitchM]

Those containers are meant to be hidden within your waterfalsl structure and come in a few different sizes. You can get ones that are fed from the top or are fed from the bottom.
If you want to try a DIY project, check out the DIY sction, there are a few different sytles. The tricky part there will be to find a container that is the right size for your project. https://www.gardenpondforum.com/forums/diy-do-it-yourself.9/

Adding aeration would be a good thing, but I don't see where you could hide an air pump in your landscaping.
Anything you can do to add water circulation or aeration would help because it will suspend detritus and give the aerobic bacteria a chance to break down excess nutrients that sound like are building up.
Adding aeration and circulation will also help cool down your pond because it will increase evaporation.

 

[gardenlady]

It can't get within the waterfall as the rocks are all cemeted around it which is why I'm stuck adding it into the pond itself. The pump is at the bottom of the pond in front of where the bog is. I could probably add the areation and hook it up replacing one of the spitters..at least I think so. They do have a flat stone on top of the pump so I might be able to put the bio filter there? Since they come to clean the pond out once a year that could be cleaned then also if it needed it. BTW..Love your greenhouse!

 

[HARO]

The simplest solution to green water is a UV clarifier. Should be fairly easy to hide somewhere near the pond.
John

 

[MitchM]

It can't get within the waterfall as the rocks are all cemeted around it which is why I'm stuck adding it into the pond itself. The pump is at the bottom of the pond in front of where the bog is. I could probably add the areation and hook it up replacing one of the spitters..at least I think so. They do have a flat stone on top of the pump so I might be able to put the bio filter there? Since they come to clean the pond out once a year that could be cleaned then also if it needed it. BTW..Love your greenhouse!

The problem is that biofilters need to be cleaned, more than once per year, depending on how much work it has to do, and to have one submerged in the pond makes that very difficult. You would need to lift it out somehow without having all the collected detritus fall back into the pond again.

Do you have any mechanical filtration for the pond, other than the batting material that the spitters are directed at?

When was the last time your pond was cleaned out? I'm a little concerned about your dying fish. Fish shouldn't be dying without understanding why. If you have a dead fish lying at the bottom their decomposing body will give off ammonia which could feed an algae outbreak.

As Haro suggests, UV will clear up the water too, but the algae that it kills will need to be filtered out eventually.

(thanks about the greenhouse)

 

[Tula]

What about something like this? It could sit on the edge of your pond. It's a very good shower filter.....but you'd need something to filter the water prior to entering it.

I have a similar set up to you, with a stone patio built around the pond. I "hide" my pressurized filter behind a hydrangea. Could you "hide" one behind the shrub behind your waterfall? It's something to think about, because as the koi grow, you'll need more filtration.

 

[gardenlady]

Well we had professionals build the pond for us so I assume we have a filtration system and it passes through the bog. Maybe the bog is the filtration? My husband built our pond originally but when we went way bigger I had someone come in and build it so I'm not that knowledgable about the mechanics of it. I take care of maintaining it. I like the look of that and I'm sure I could sit that on the perimeter of the pond. It depends on how large the pressurized filter is in terms of hiding it behind the shrub... It does get a lot taller but not tons fuller.

 

[koiguy1969]

THE GOOD THING ABOUT PRESSURE FILTERS IS YOU CAN BURY THEM!

 

[gardenlady]

Well I was just looking at this one but couldn't I stick it in a pot or cover it with a faux boulder? *not sure how large it is yet* The instructions for this one do show it buried which I guess wouldn't be too difficult depending on the size. I really like the way this one works. We're heading out to our local pond place now to talk to them about the options.

hmmm..doesn't look clickable for some reason but I guess copy/paste

 

[koiguy1969]

I had a fishmate pressure filter.. I buried a 5 gal bucket and filled it with gravel to the point where my filter sat where I wanted it. ohh.. drill holes in the bottom 1/2 where the gravel is for drainage.