Do I Need This Size Pump/Filter and How About Algae Scrubber?

[abrogard]

We've got a bathtub in the back garden converted to use as a fishpond.

Currently it has only four small goldfish in it. We've had the setup for more than a year now.

It has some water plants in there, transplanted from a nearby river.

That'd be about 50 gal of water there.

What's brought me here was a search for some way to cut down on the green in the water - the algal growth.

Found an article about algae scrubbers whilst googling around. article.

It looks to me like what I need.

If I can get the water clear, and yet remain healthy, then I can landscape the bottom of the thing and make it altogether a better exhibit.


Currently we're running a 200 gal/hr pump feeding a plastic wool filter and I'm having serious doubts about that.

It doesn't cut down the algae, totally ineffective. It is merely a mechanical filter and i don't see we need that much mechanical filtration. We did it only because of the widespread info that water should be filtered at a rate of about 4 x tank volume per hour.

So it seems to me it's basically useless. I simply don't need that size pump/filter despite the info I've read. That info was mainly for indoor acquariums I guess.

An outdoor setup is quite different isn't it?

Any thoughts on that will be much appreciated.

And any advice on an algae scrubber for our setup - the point being that perhaps we don't need lights? The fierce sun hereabouts is what's promoting the growth of algae within the pool, seems to me I should be able to make a scrubber that utilizes that same sun, right?

My current filter that I'm having doubts about, is enclosed - hence it's dark in there. Black sludge grows in there. I imagine it's doing no good as an algae scrubber. As I say, it's just working as excessive mechanical filtration I think.

For a while there the filter setup was resting on a flat steel plate laying on top of the pond. The spillage, constant overflow from the filter began to get seriously thick and green. It was exposed to the sun you see.

Look to me like I had an algae scrubber operating there and then, what do you think?

 

[JohnHuff]

We've got a bathtub in the back garden converted to use as a fishpond.

So how do you take baths now?

 

[JohnHuff]

The answer to your question is a very encompassing one. It's like asking how do you keep fish. There is no one single answer. I think my first questions would be do you test the water and what kind of results you are getting. But there are so many questions to ask. Your tub might be getting too much light, you might be feeding your fish too much. How green exactly is your water? 4x tank volume I think is too much. You might need a tighter filter.

Have you considered using uv? I think this might be your simplest answer.

 

[abrogard]

How do we wash now? They're only little fish, John, don't take up much room.

Using UV? What for? For light? For an algae scrubber?

Okay.... googled a bit and learned a bit.... you mean those UV contraptions that kill algae, I think, is that what they do? Is that what you're thinking?

Might be right, too..

 

[shakaho]

The first thing you should do is build a filter. There are many filter builds in the DIY section. A five gallon bucket is a fine filter container for your little pond and you can scale down from the larger filter builds.

Add the algae scrubber to the outflow of the bucket filter. I almost wish I had green water, because I would love to find out how well these work.

 

[JohnHuff]

Add the algae scrubber to the outflow of the bucket filter. I almost wish I had green water, because I would love to find out how well these work.

Just a fancy name for growing algae in a separate place so that it takes away nutrients from the pond.

 

[Jason]

A 200gph pump is perfect for 50 gallons of water. The smaller the body of water means more recirculating that it needs. A 55 gallon Aquarium needs to cycle at least 4 times an hour where a 2,000 Gallon pond need to only cycle at least 1/2 an hour. You can get away with less in an indoor aquarium way easier than an outdoor body of water as it is exposed more to all elements. You can buy a 9w UV clarifier on Ebay or Amazon for $35 and it will clear your pond up dramatically along with good mechanical filtration and Beneficial Bacteria like Bio filtering.

Can you take a picture of your pond tub and filter setup along with water clarity? How often do you clean your filter?

 

[abrogard]

Thanks for that.

On what basis do we calculate what amount of circulation is required for what volume of water?

I'd like to finish up with an inground pool but first I need to completely master, understand, the dynamics of this tub. If I can't do that there's no point proceeding further.

Got a bunch of pics on google pics here:

https://plus.google.com/photos/1107...s/5969261212226945841?authkey=CIDv1MW836iiggE

Looks like a big mess. Have to have the chicken wire to keep cats and birds away.

The home made filters are just filter wool and plastic containers. From plant pots to buckets I've experimented.

Took a shot of the black gunk I get in them.

A corner of water in an icecream container might give you an idea of how green the water is.

Plus the shots of the pool. You can see how the fish are visible only in the top two inches or so.

You can see there's a little shade cloth awning over it. The shed it stands against lies N-W so the water is shaded from all direct afternoon sun completely.

I'm thinking my recirculation is mainly ineffective.

All the good it is doing is aerating the water a little. The little black filter (made from the plant pot) probably does more in that line because streams of water splash more.

There's no solids being generated at any great rate.

There's no algae filtering going on.

And it's not hosting algae to create an 'algae scrubber' - i.e. grow it elsewhere so's it doesn't grow in the tank as someone said.

So it's just crap.

What do you think?

p.s. clean the filters? When they are about 60 - 70% black gunk I change the wool.

 

[JohnHuff]

I don't think gph vs volume is set in stone. The gph will also vary depending on the height the water is raised up. My circulation is just over 1X, i.e. 1000gph pump for a 800g pond. I don't like strong flow that much. YMMV.

 

[shakaho]

Just a fancy name for growing algae in a separate place so that it takes away nutrients from the pond.

Oh, I know the principle, I just would like to test how well it works. But I can't get green water in my ponds so I can't do the test.

 

[shakaho]

I use pumps like this for stock tanks from 40 to 100 gallons. I have tried a smaller pump or two, and found they were junk which broke down in a few months. A 264 gph pump does not produce much flow. I use DIY upflow biofilters of 5-10 gallon capacity.

 

[JohnHuff]

Oh, I know the principle, I just would like to test how well it works. But I can't get green water in my ponds so I can't do the test.

Try overfeeding and shut off your pumps for a day or two.

 

[abrogard]

That's the kind I use. Too similar to be anything but the same thing. From China. I get them from eBay. Mine run on 240V. I'd rather they didn't but I can't find affordable 12 volt equivalents that work.

What is a 'DIY upflow biofilter' ? A do it yourself filter that breeds algae in order to de-nitrify? What's the 'upflow' bit mean?

 

[Jason]

"On what basis do we calculate what amount of circulation is required for what volume of water?"

and what john said "I don't think gph vs volume is set in stone."

I don't either, I was always taught that on here though when I first started out along with pet store employees and other local pond and aquarium owners. My 500 gallon pond has close to 2,000GPH pushing through it and has worked well for me going on a year now. It's all trial and error, giving you my opinion of what works for me might not work for you, But after having 2 ponds with green water clear up in 2 days after installing some sort of UV clarifier rather it be built in your filter or stand alone, IT WORKS lol

My new pond will be around 3,000 gallons but I will probably only push just over that after 2 pumps, 2 filters.

Here is my first DIY filter that I made for my future pond (2 of them are built) and it is in test phase in my small 400 gallon pond and has cleared it up dramatically over the last few days, something that the in pond pre-filters do not do a good job at from my experience, Outside pond filters rather they be gravity or pressurized are much better iMO, Here is the link, hopefully you can build something on a smaller scale like it.
https://www.gardenpondforum.com/topic/13420-27-gallon-container-filter/