Simple Bog Building Questions

[shakaho]

If you have 15 goldfish after two years, I wouldn't worry about the population exploding. You do have more fish than is ideal right now, so i t wouldn't be a bad idea to get rid of some, but once you have a few medium to large fish in a fairly small space, they will consume almost of the eggs and tiny fry very quickly, and other predators will take care of most of the rest. My front pond is the size of yours, and in the two and a half years since I added 1 year old goldfish, exactly one fry (named Wonder) has survived, despite almost continuous spawning for six months of the year and sporadic spawning during the rest of the year. The really bad goldfish population explosions occur when someone adds a bunch of feeders to a large pond. They will spawn many times before there are enough large adults to consume the eggs/fry.

Here's a link to a very easy to build container bog filter.

 

[addy1]

Nice build

 

[HTH]

Off topic but I would like to respond to Fishylove regarding dragonflys

Very true HTH! I can't seem to get dragon fly's to breed ( if thats what they do Lol) around my pond. I wonder if you can buy dragon fly larvae like you can buy tadpoles?!

I am sure I seen dragon fly egg cases for sale. Not sure how common that is.

On the other hand I am going to be cleaning out the big pond this week, with luck we will start moving the lilies out today. I expect to encounter a goodly number of dragonfly nymphs. If we can save them I would be HAPPY to send them your way for the cost of shipping. I do not know that they would survive shipping but it may be worth a try. Thinking they eat a lot and will be very hungry or dead in the time it takes to ship.

I love seeing the adults around the pond.

Found them for sale
Seems they may also be in fishing bait stores.

Seems they eat each other so they would have to be packed one to a bag or maybe a baby food jar. Fun stuff. Info

 

[Minnow]

I'm not too sure what substance you're looking to filter, but it sounds like your main concern is fish health because the fish load is growing. So ammonia and nitrite are the targets I assume. You want a bio filter.

I like bogs for many reasons, but bio filter isn't one of them. Especially in a small pond. A Trickle Tower is just as simple to make, same cost but convert 30 times more ammonia and nitrite for the same size. Plus a TT never has to be cleaned out while bogs do fill with muck.

Isn't a biofilter easy to maintain?

Oh and a bit of news!

I was able to acquire two 40 gallon stock tanks today and I began thinking about the bio filter idea. I guess there is no going back now, huh?

The funny thing is, when I got home and placed the tanks next to the pond, it seemed like all the water in my pond would fit in both stock tanks!

Before I even consider drilling into one of them, I am still trying to grasp not only the concept fully, but what parts I will need.

Ok, I do get the concept a little bit. I have read umteen zillion different ways to build a bio filter, and while simple, it seems like everyone has a different way to build one.

I think the first thing I need to do a full drain of the pond. If I eliminate the shelves I built, I would have more water capacity and then I can add shelves as need with brick and flagstone.

Once that is done, I can build the filter next to the pond and have it where it will be opposite the submersible pump.

What diameter input and outputs do you all recommend? And what is the best way to seal the openings on the tank?

Should I use both tanks or just one?

Any other advice on how to simplify this?

 

[Waterbug]

So, I could build this in a 10-15 (even a 20) gallon planter? Water pumped from the bottom of the pond (at the one end) into the top of the planter (at the other end), gravity fed through the coarse sand and out the bottom?

It can be scaled to any size. Basically what you'd be doing is creating an aquarium filter. 250 gal pond, 250 gal aquarium, not a lot of differences. Some, but a lot more in common. And the really good thing is there is just tons more info on the web about aquariums. People in that hobby have been real serious about clear water and keeping fish alive for a really long time.

You can find lots of DIY sand filters and many more. Very detailed, lots of experience. Unlike ponds which are much easier and don't require the same level of expertise.

Coarse sand? Will the 50 pound bag of play sand from a Lowe's or Home depot work?

Play sand is fine. Mason supplies sell coarse sand. Sometimes called sharp sand. You want to wash it first. It's up to you how fine or coarse. Fine sand does trap smaller particles so cleaner water but clogs faster. I was thinking coarse might be a reasonable middle ground.

I still think a sand filter is not a good choice for clear water in a 250 gal pond. UV and/or water changes is way easier and more effective. Bog, sand filters all do what they do but they are not easy to tweak to get particles to settle. Flow, media size, size of filter, what's making the water unclear, are all factors, and that's a lot of factors imo.

 

[Waterbug]

Isn't a biofilter easy to maintain?

The good ones like Trickle Tower, Shower and moving bed require virtually zero maintenance. The less effective that use submerged media, like Skippy, can require to be cleaned often and cleaning isn't fun imo. With a bio filter the two things go hand in hand. If it needs to be cleaned it's not going to be as good a bio filter because the bacteria can't do their job when covered in even a tiny bit of muck.

Ok, I do get the concept a little bit. I have read umteen zillion different ways to build a bio filter, and while simple, it seems like everyone has a different way to build one.

I think that's the main attraction DIY filters have to hobbyists. They have to be inexpensive, but not cheap, simple enough that most people could build it but complex enough that the builder is proud of an accomplishment, and impressive looking enough to show others. They're built for entertainment. Function is not a concern. They of course always say what a great filter it is because that's more impressive sounding. You'll almost never read about the builder taking the 2 minutes to actually test water to see if the filter works. Instead they just look at it proudly and assume, obviously, it must work.

On the other hand a pile of rocks with water running over it isn't impressive at all...except that it's 30 times better at its job. But if a person isn't testing water what difference would that make?

What diameter input and outputs do you all recommend? And what is the best way to seal the openings on the tank?

Not sure what you're building so don't know. Generally the output is 2x the input.

Should I use both tanks or just one?

To me, filters are only tools. The number/size depends on the need. But there's no big downside to as many as you like except for cost and an increase risk of leaks and maybe more maintenance depending on the filter type.

Any other advice on how to simplify this?

I'm not really clear on your goals. First I thought it was keeping a larger fish load alive, then it was clear water...now both?

So I'll hit both.

Clear water: UV and occasional water changes. Net out debris once a week in the summer. About 2-4 minutes. I used to do this pretty much every time I fed the fish. Surprising clear water.

Keeping fish alive: Small strawberry pot trickle tower. May never need to be cleaned. Test water to see if more bio is needed.

To me there are some downsides to smaller ponds. But there are some upsides too, like simpler cleaning. Seems like you're trying to add a lot of complexity that larger ponds need and getting the worst of both worlds.