Question about suction filter

[biederboat]

Hello,

My first official question as a new member! Looks like a great forum. We've had a koi pond for nearly 20 years and I'm trying to make steady but "calculated" improvements towards a pond that looks better and is easier to maintain (it does tend to stay much "greener" than I prefer). While there's a ton of things I have questions about, I'm going to start with a very fundamental question.

To keep it simple and not get too many other factor involved, our filter is a suction system that sits at the far back/bottom corner to hopefully take the most "stale" water. The filter itself is a 5-gallon bucket with about 6 "charcoal-impregnatted" mesh disks (sicks through a fitting that is on what would normally be the bottom of the buck and the filters are placed against from the "top". We clean and replace the 6 disks as a batch (hose them off) and peel them back one at a time until the last one clogs (pretty much muck/algae/debris).

My main question is does this type of filter tend to remove good bacteria, especially when I hose out the filter elements? Is there a better media I could use?

Just a few other notes, we have a bucket at the top of the pool that sits over the opening. A lot of the "much" that makes it through the filter settles into this upper pool and we have made some improvements to make it easier to clean out. We can stop the pump, open a valve and drain and hose it out, running all the much out the drain. We used to have some just gravel it in but that was hard to keep out of the drain and it just trapped a lot of the much.

Thanks for any help. I'll have lots of other questions as I continue on but just wanted to start with something fundamental.

BB

 

[Lisak1]

I don't know if I understand your question completely, but I can tell you this - yes, if you use hose water to clean your filter media you are most likely doing away with the good bacteria. Is there a way you could rinse the media in pond water instead?

Can you post pictures of your filter set up?

 

[Tula]

Welcome! I too have koi, big waste producers! I clean my filters with the hose, as they'd never come clean enough if I cleaned them with pond water. I've never had a problem, maybe because my pond is 10 years old....I figure there's enough "good bacteria" in the pond .

Again, welcome and we'd love to see pictures

 

[biederboat]

Lisak1, you have understood correctly, I am literally hosing off the filters from the spigot. I'm reluctant to use pond water since it seems like I'd be putting the "crud" right back into the pond. I could rinse them off in the upper pool as they might settle out somewhat before going back into the main pool. Is there something that would filter the crud but not absorb the bacteria, like a fine mesh screen?

Tula, thanks for your post. Can you tell me what kind of media you use?

Thanks,
BB

 

[Lisak1]

I'm reluctant to use pond water since it seems like I'd be putting the "crud" right back into the pond.

I don't have a filter, so I don't have this issue, but we do use a small submersible pump to pump water from the pond to water the gardens. Could you do the same to wash your filter media I wonder?

 

[HARO]

One question,Biederboat; Are you on a well or city water? And as for washing out a filter with pond water, You would use a BUCKET of water to rinse the media in! Do NOT swish the media around in the pond.
John

 

[biederboat]

I don't have a filter, so I don't have this issue, but we do use a small submersible pump to pump water from the pond to water the gardens. Could you do the same to wash your filter media I wonder?

Hmmm...possibly. I'm still wondering if I'd wash the good bacteria out, even though it would be with lower pressure water. I'm an engineer not a biologist LOL!

 

[biederboat]

yOne question,Biederboat; Are you on a well or city water? And as for washing out a filter with pond water, You would use a BUCKET of water to rinse the media in! Do NOT swish the media around in the pond.
John

Okay, another option. We are on city water so it has chlorine and other things I'm sure. Sorry, still new to the learning part of all this, are you saying that sloshing around in a bucket of water (presumably pond water) would remove the algae and not the bacteria (i.e. it clings to the filter media)?

BB

 

[HARO]

The bacteria removed by the sloshing would be largely dead anyway. Living organisms tend to hang on quite tenaciously. Fluid-bed filters keep the media moving for this very reason, to get rid of dead bacteria and permit more to grow in its place. The thing is, the chlorine in your (hose) water will kill all or most of the bacteria, depending on length of exposure.
John

 

[biederboat]

Here's a few photos finally:

Overall pond (upper pool in far back, filter sucks from the bottom corner nearest you in the photo, pump is in far back corner):

Filter housing "floating" on top, it's normally at the bottom while it's working but on rare occaision rises if some air gets trapped. We also pull it up for cleaning (pump turned off) when we replace the dirty filters with clean ones. To "peel" a dirty filter, you just pull up on the tether lanyard and raise it near the surface, reach in, pull out the outer filter and let it sink back down.

A "dirty" filter element (made from charcoal impregnated mesh). They do rinse off fairly quickly. Sounds like this should be done in a bucket of pond water which is not returned to the pool after cleaning? Also, this was running quite "slimy green" until we did about a 75% water change over the weekend.

Thanks for the help!
BB

 

[Lisak1]

Love the pictures! Did you change that much water to battle the slimy green?

 

[biederboat]

Love the pictures! Did you change that much water to battle the slimy green?

Yes, very much so. We hadn't done a water change in a LONG time and, to be honest, I've never really tried to learn the whole pond chemistry thing. I have to either get this thing under control or give it up. I don't mind regular maintenance to keep it looking good but I hate a constant battle that I'm always losing. I know the filter is just a part of it but I believe in making deliberate and meaningful changes and measuring the result. No more "shotgunning" troubleshooting.

BB

 

[HARO]

OK, BB, just re-read this thread to clarify a few things. Correct me if I'm wrong. You place all six filter pads in the pail, and remove one at a time as they clog. So far so good. Each filter pad is hosed clean, THEN I assume it is left out of the filter until the sixth one is cleaned, and all are replaced. The beneficial bacteria on the pads need two things to stay alive: water and oxygen. Depending on how long a pad is left out of the filter, the bacteria will probably all be dead by the time you replace them, whether or not you hose them off. In other words, if the chlorine doesn't kill them, the drying will! The one good point in this system is that the last pad cleaned will retain most of its bacteria (as long as you don't use the hose), and will probably re-seed the entire filter. By the way, only a small percentage of the beneficial bacteria in the pond are in the filter; they inhabit every square foot of liner, the surface of every rock or ornament, and coat every plant.
A few more questions, if you don't mind. How many fish and what size? How long does the six-pack of filter pads last? By that I mean from six down to cleaning the last one. And is there any chance you could conceal an external filter somewhere around the upper pool?
John

 

[biederboat]

OK, BB, just re-read this thread to clarify a few things. Correct me if I'm wrong. You place all six filter pads in the pail, and remove one at a time as they clog. So far so good. Each filter pad is hosed clean, THEN I assume it is left out of the filter until the sixth one is cleaned, and all are replaced. The beneficial bacteria on the pads need two things to stay alive: water and oxygen. Depending on how long a pad is left out of the filter, the bacteria will probably all be dead by the time you replace them, whether or not you hose them off. In other words, if the chlorine doesn't kill them, the drying will! The one good point in this system is that the last pad cleaned will retain most of its bacteria (as long as you don't use the hose), and will probably re-seed the entire filter. By the way, only a small percentage of the beneficial bacteria in the pond are in the filter; they inhabit every square foot of liner, the surface of every rock or ornament, and coat every plant.
A few more questions, if you don't mind. How many fish and what size? How long does the six-pack of filter pads last? By that I mean from six down to cleaning the last one. And is there any chance you could conceal an external filter somewhere around the upper pool?
John

Hey, thanks for really putting some thought into this! You're pretty close. I stack the dirty ones as they are pulled so they stay somewhat wet but, yes, they can also dry out. I don't hose them off until the last one is dirty. Right now each new filter lasts about 2 hours so the whole batch gets recycled about once a day (before the water change it could be 2x daily). I'm thinking, from your answer, that I should have a "slosh bucket" and then maybe keep them in some kind of net in the pond? BTW, the last pad cleaned was usually the last one pulled and often the first one back in (just by the order in which I did it) so, unless the bacterial are strong swimmers it would have a hard time reseeding the other filters. But maybe that just doesn't matter that much?

About 5 larger koi, around 18-24", about 4 smaller ones, 8-10". At least two larger bluegill that I know recently had a BUNCH of babies that I tried unsuccessfully to trap or net but I have not seen them recently (although they are dark and hard to spot, especially with the bad water).

We used to have a "pressure" filter in the upper pool which was red lava in mesh bags (the pump feed the bottom of the upper pool and I adapted a bucket with holes to allow water up the bottom, through the bags and then out holes in the top of the bucket which was capped with a nice flat rock). It seemed to work "okay" (we would clean I'm guess around once/week I think just hosing off the mesh bag). That was at least 4-5 years ago. When we first switched to this system the pond cleaned up really nicely and I thought I was in heaven. It's been a long and slow downhill process to where we are today. Over the winter it is usually crystal-clear but even this year it was not quite there. To answer your question though, I do have options on putting some kind of filter in the upper pool. I do like to have some kind of strainer filter to at least keep the crud out of the strainer in the pump (Sequence 150 with the standard strainer in front of it). If there's no pre-filter the pump strainer is a pain to clean since the water doesn't always back-flush from the upper pool when turned off so I tend to lose that water (have to drain it to open the strainer). Hopefully that makes sense. But if we went back to a filter in the upper pool I could just add some kind of fine mesh to keep stuff from getting sucked into the pump strainer. Looking back, the pressure filter generally seemed to run longer (which maybe kept the water more oxygenated?) and a big part of what was clogging the strainer was that kind of plant that grows in large "furry strings" (sorry, can't remember what it's called) but I finally eradicated all of that stuff).

Thanks again for a good post, hopefully that answered everything okay.

BB

 

[HARO]

All righty, then! So I can ASSUME that you have a fairly high fish load in this pond, which will definitely contribute to any algae problems. Don't mind me if I ramble a bit, I'm just sorta thinking aloud, as it were. Do you ever test your water, especially for ammonia? Curious bugger, aren't I? That long, stringy crap is called hair algae. It's called a lot of other things too, none of which are printable in a family-friendly forum! The relationship between various algae is complicated, but let's just say that some algae will produce substances that retard the growth of other algae. Hair algae has been shown to kill off green-water (single-celled) algae under some conditions. Can you see where I'm going with this? By "finally eradicating" the slimy stuff, you may inadvertantly have created a different problem! Hope I haven't lost you yet. So, the filter I'm thinking of would not be IN the upper pond, but behind or beside it. this location would allow you to have a drain valve at the bottom of the filter which would permit the draining of collected sludge on a regular basis, like every day to begin with. A 2" or larger pipe or hose would carry the waste to a suitable location, where it could fertilize plants, or whatever. My filter set-up consists of two 45 gallon olive barrels, the first one about a foot higher than the second. Water is pumped down through a pipe to a swirl apparatus which sits about 6" off the bottom of the first filter. it percolates upward through about $100. worth of dish scrubbers, flowing through a 2" pipe into the top of the second filter. Virtually all the crud is left behind in the bottom of the first barrel, and can be drained via a 2" slide valve and about 40' of hose leading to a low spot in the yard. Occasionally, I'll dump a pail of water in the top to help the crud along, but this year I haven't had to do that yet. OK, if rou're still with me, this is the good part! The water now flows into the lid of the second section, where a LOT of 1/2" holes spread it out so that it trickles fairly evenly over a 12" round column of bio-balls, and drains out the BOTTOM through another 2" pipe, and back into the pond.
Now, to the point of all this rambling! The second barrel is my biological filter. The column in the center is always wet, but never submerged in water. This permits the maximum growth of aerobic bacteria, which break down your ammomia/nitrites into nitrates, which feed the plants. This stage is totally absent in your filter set-up! Muck builds up so fast that tbe bacteria are smothered in it, and can't do their job! I for one believe that this is the biggest problem facing you, and one that must be addressed.
John

Please don't get me wrong, I'm NOT trying to be critical. I AM trying to find a solution!
Time to go and ice my typing finger.