pond filtration...what is the correct "order"?

[parker002]

Now that my father-in-law has passed, the pond has become somewhat of my responsibility. Since they dug this thing, my in-laws have had issues with canister bio-filters.

Recently, my mother-in-law replaced her 3rd powered canister (3-stage filtration with sponge/floss/bio balls) with an unpowered Tetra canister. It really only does biofiltration (it only has small filters on the intake.

The thing leaks, like they all have, and it fills with algae and muck rather quickly. I'm wondering if maybe her setup is "out of order".

Today, she has a powerhead/pump directly plumbed to the canister. The powerhead/pump is in a mesh bag but otherwise has no real filtration on it. The pump output is plumbed to the waterfall, which contains a 3-stage filter (bio balls/sponge/floss).

The majority of the mechanical filtration is occuring at the very end of the water circulation and I'm wondering if that's part of her continual problems.

[Carl]

Pressurized pond filters can vary in their methods of filtration, but generally most are primarily biological in their design.
I personally have used the Tetra model with reasonable results.
The use of products such as Matrix in your pressurized filter may help improve its function

What I suggest is using rock (volcanic rock works best) as prefiltration prior to entering the pump. If there is extra muck, sponges can be added to after the rock and next to the pump inlet.
Separate Pond Sponge filters may help too.

Also I strongly suggest a well built Veggie filter, especially if you have a rather mucky pond which seems to be the case.

A Pond UV Sterilizer also helps by clumping algae and bio matter that it does not outright destroy, allow it to be more easily consumed by heterotrophic bacteria in the pond.

Look over some of the suggestions in this article as well:
Pond Care Information

Carl

[parker002]

Are there moving parts inside of the Tetra canister that could be damaged using something other than the little plastic "bio stars"? Beyond that though, I don't think lack of bio-filtration is an issue (I've never noticed ammonia spikes or anything like that) - the issue is that the canister just becomes a clogged mess of dead and live algae.

I have been reading your articles in my spare time. The Tetra is leaking bad enough that it has to be sent to the manufacturer to be serviced. My mother-in-law was concerned about a biofiltration deficiency in the interim, so I actually made a slightly-modified version of your DIY bucket pre-filter. Her pump won't fit in a 5G bucket so I did this:

• I took a kitchen waste basket and cut the top half off.
  
• I put the pump in the bottom and filled lava rock all the way around it.
  
• I cut a piece from the leftover wastebasket to cover the half of the rock directly above the pump intake. (My thought was by inserting a piece of plastic as a baffle, it would force pump to draw water through all of the rock rather than just the rock next to the intake.)
  
• I put two pieces of bonded blue filter floss on top.
  
• I attached an old piece of fish net (using upside down hooks to allow for easy removal) across the top to hold everything in.
  

So far it seems to be working quite well for how cobbled-together it is.

On the subject of veggie bio-filters, we have some plants in pots:

• large wild cattails (1G pot, non-dwarf, 5 stalks, just dug them up from the ditch the other day
  
• a few dozen water hyacinths (free-floating)
  
• variegated black taro/elephant ears (1G pot, 3 plants currently)
  
• pretoria species water canna (3 separate 1G pots, small plants with some new growth)
  
• lilies (1G pot with large rhizome, another 1G pot with 3 small rhizome cuttings, plants are small for both)
  
• an unidentified bog plant - my wife threw away the dang ID card! (on a side note, can anybody ID this plant?)
  
  
  
  The big issue is that we have Canadian winters here anymore (temps in the teens and wind chills below zero) so we have to pull almost all of our plants to avoid them dying. That means come spring, the algae is way out ahead of us. None of our plants are well-developed (outside of the hyacinth that spreads like an infection) and it's already June. By the time they grow in well, it will be time to remove them again.
  
  Finally, I plan on getting a UV as soon as I can afford it. I love the TMC UV25 I put on my 55G aquarium.
  

[Carl]

I am a bit confused by the "moving parts" in your Tetra Filter, generally these are run by an external pump.
*My suggestion was not that you lack bio filtration, but that certain mediums can both mechanical pre-filter better and perform more efficient bio filtration (even bio de-nitirifcation), thus resulting in less mulm in your filter and pond.

*I think you idea for the pump "rock pre-filter" should work quite well.

*As for cold inter bog plants, taro/elephant plants generally will not work.

Here are a few suggestions:
Arrowheads
CatTails
Rushes
Water Iris (these are by far my favorite as I have had great success with the effectiveness of these in pond veggie/bog filters

As for Bog/Veggie filters, the idea is to have these remove nutrients prior to being broken down or even decaying on the bottom or somewhere in the pond, often resulting in mulm/gunk and green water too.

Carl

[parker002]

After taking apart the Tetra, it appears the laterals at the bottom of the central tube "spin" or at least they could, given enough water pressure. Perhaps they don't and are just loose like that to allow for a good fit. It is most definitely run by the external pump.

Would it be prudent to expand the biofilter capacity of my DIY pre-filter and do away with the canister altogether? As I mentioned, she's had nothing but problems with them and eliminating it leaves us with no reason to have any hoses out of the water. This simplifies winterizing, since the hoses HAVE to be submerged to prevent freezing.

We have some irises that may work in the other garden, I'll give them a try...

[Carl]

I have actually had good results with most all pressurized pond filters I have used, so I would have a difficult time recommending to end its use unless you can make up for it with a good bog filter as well (which will take a season to mature).
Also this rock pre-filter often does not accumulate waste the way your pressurized filter can.
My suggestion is to only disconnect during the winter months.

As for the Iris, I have tried terrestrial garden iris and failed, so from my experience it needs to be bog iris for pond use.

Carl

[parker002]

Cool, thanks for the info.

Any idea what that plant is in the pictures?

[Carl]

Jun 16, 2011 22:01:05 GMT -5 parker002 said:

Any idea what that plant is in the pictures?

Sorry, I have not seen this plant before.
I did look around a bit on the internet as well, but could not find it.

Carl

[parker002]

Me either. ROFL

I think it may be a Queen Victoria Cardinal flower. If that's the case though, then I have a different plant I can't identify (because the store had it labelled as a Cardinal Flower).

[Carl]

Jun 21, 2011 13:56:28 GMT -5 parker002 said:

Me either. ROFL

I think it may be a Queen Victoria Cardinal flower. If that's the case though, then I have a different plant I can't identify (because the store had it labelled as a Cardinal Flower).

It does look like the Queen Victoria Cardinal, but I read this:
"A moisture loving perennial during the growing season, but needs good drainage when dormant."
hoffienursery.com/index.cfm/fuseaction/plants.plantDetail/plant_id/407/index.htm

Which would mean a bog environment should kill it?

Carl

[parker002]

From what I've read, it's dormant during the winter, so it wouldn't be getting water then anyway. I don't have it submerged, it's actually potted and sitting in about 1 inch of water. I'll probably just bring it in for the winter anyway.

Back to my pond, I'm losing the algae bloom battle.

I've re-inserted the Tetra into the mix and removed my DIY pre-filter (slightly flawed design was restricting water flow too much .

I tested the water and ammonia and nitrites are 0. Nitrates are actually low which might explain why my plants are so spindly.

This leads me to believe I have a phosphate issue or something else that is contributing to algae growth. I'm just not sure what to do at this point to get out ahead of it.

[Carl]

Outside of a UV Sterilizer, there is no "quick fix".

I still strongly recommend getting a full bog/veggie filter going, but these take an entire season to hit their stride.

Using products such as Volcanic rock or better, Matrix in your filter can help, but these too take about 6-8 weeks to really work.

SeaChem Purigen can help, but the quantities needed for a pond are generally cost prohibitive

Have you looked over this article:
Pond Green Water

Many of the suggestions help, often only marginally, but when done together these suggestions can make a huge difference.
One suggestion I have used that does work is magnets, as these remove iron from the water that feed algae (these by themsleves rarely cure green water, but are one of many small steps forward)

Carl

[parker002]

The mother-in-law picked up a cheap UV at the place she buys her stuff (I don't agree but it's her pond and her money . It's a Sunterra 18W and in just 2 days, it's made a HUGE difference.

I redid my pre-filter design using a Rubbermaid tub. I cut a 4" x 8" rectangular hole in one end and used nylon bolts to attach a $1 rubber sink mat to it. I placed the pump in with the inlet opposite the hole and filled the whole thing with lava rock. It's working GREAT - we haven't had water movement this good in a long time.

She still needs to send in her Tetra bio-canister for repair and she was going to buy another one as a spare. They're well over $200 and I'm not sure they are worth it, personally. She looked at Sunterra at her place and they're $150.

I've got her talked into a TMC Clearstream 1200 after reading about them on your site but they're out of stock! Any idea when I might be able to get one?

[Carl]

The Clear Stream 1200 has been discontinued by the manufacturer

However the 600 is 75% of the 1200.
We have though of selling the 1200 UV Version (since we sell the UV versions of the much larger Via Aqua Pond Canister Filters), but I really do not like selling a product that will cost more for a marginal additional piece of equipment which all Pressurized Filter plus a UV are (UVs mounted to Pressurized filters are often ineffective by the design and flow rate with the Tetra, Clear Stream or Via Aqua no exception)

For the money the Clear Streams are as good as the Tetra (which cost much more), and the Via Aqua are much larger in capacity.

Carl

[parker002]

So would you recommend buying the 600 as the "spare" and put the Tetra back in when it comes back?

[Carl]

What size is your pond?

Assuming this is not a pond over 1500-2000 gallons I would say this is a good idea to have both.

Regards;
Carl

[parker002]

The pond is about 1250G. I did figure out why the Tetra is leaking - it's too small. She originally bought the Tetra on the recommendation from Tetra that it was designed for ponds up to 3000G. However, in reading up on it, it does indeed say it can handle ponds up to 3000G but it also says the maximum flow rate is only 1250gph. Her pump puts out 2500gph max and at 5' of head height still puts out over 1500gph. I used to think it was a coincidence that the Tetra would stop leaking over time but it now makes sense - as the pump intake clogs, the flow rate slows and the canister can actually keep up. If I rinse out the pre-filter box, the pump literally blows water out of the seals in the canister.

We have a 950gph pump on the surface skimmer. I am going to plumb it to the canister since it has no bio-filtration today. We'll still have the pre-filter box (which I filled with bio-balls and chunks of sponge since lava rock made it impossible to lift from the bottom of the pond! ) and lava rock in the spillway, so I actually think we'll have more net bio-filtration in the end by putting the canister on the smaller pump.

On a side note, by Monday morning I could see the bottom of the pond. By Monday night, the water was as clear as glass. That cheap Sunterra UV worked like an absolute miracle.