pea soup mystery

[JayDogg]

I'm in a quandary about my new bowl of pea soup. A couple months ago I undertook some major projects to clear up the pond, which was slightly cloudy at the time. After building two biological filters I was (seemingly) successful and the pond was crystal clear all the way to the bottom (3.5 feet down). It stayed very clear for several weeks... then BAM!

Over the course of a few days, or maybe a week, it went from clear to opaque and bright green. At this point I can't see more than 6" and can only see koi when they come up to eat. With the weather warming up, I expected to see some algae growth, but this is crazy. I think it had to be caused by one of two things or both...

1. Lawn fertilizer. The pond is directly adjacent to my back lawn and I know some fertilizer has found its way in. Runoff from the lawn doesn't run into the pond, but the last time I fertilized I overshot with the broadcast spreader and some fertilizer landed directly in the pond. It couldn't have been more than a teaspoon but the timing is about right for when the water went green. Is it possible I introduced enough phosphorous (or other nutrient) to spark an algal bloom?
2. Fish load. Over this past winter I took on a lot of new fish. I met a guy who had to move and was losing his pond. He's very attached to his koi, so I offered to foster them until he builds them a new pond. I expect the fish load may be too high, but it's a big pond (3500-4000 gallons). I do feed them very sparingly and make sure all food is consumed and not sucked into the skimmer.

I'm really hoping some of you experts can help me figure it out. I'm happy to provide any other information that may help. I'll also post pictures and information to document the transition back to a balanced habitat.

Thanks in advance for your help!

 

[j.w]

Quilt batting may help. Get a big plastic laundry basket or milk crate or something that you can put a bunch of the white batting into. Stick it under the falls or run a hose from a pump to it and when it gets full of green gunk take it out and hose it off and do it again and again and again or get a uv light to kill it.

 

[buckry]

I've been doing quilt batting for 3 days straight hasn't helped a single bit. The quilt batting is getting filthy, but the water is just as filled with algae. I think UV is the only way to go, simply filtering it just doesn't work.

If you've increased your fish load you've added more food for the algae, it can balance out on its own, but I think you need a UV filter taking a portion of your pump's output. Once you kill off the algae, then sticking the output into quilt batting will work great, but if it's still alive it slips right through.

I'm unhooking that third pump now, if it's not going to clean up the water I'm going to save the electricity.

 

[JayDogg]

I do have some quilt batting and have thought about diverting my pump through it. I can actually divert the entire flow through a secondary output and filter the entire volume of the pond in an hour. However, I'm sure unicell algae multiplies EXTREMELY quickly. I would think if the food is still present it'll just reproduce and replace whatever gets removed.

It seems the key would be to either eliminate the algae's food or introduce something that eats the algae. I do have a 55-gallon bio-filter that should be suitable for algae-eating bacteria, but I have no idea if the bacteria is actually present. I've seen "beneficial" bacteria for sale from various sources (example here). Has anyone tried adding it to their pond?

 

[lovinglife]

maybe you need a bigger filter. I know you added filters, but with the extra fish you may just need more. You didn't say how big your filters are or you may have to wait it out until they get caught up with the fertilizer that got in. Can you clean your filters? I am also in Idaho, only southern Idaho, in the desert where the wind blows a LOT and I live next to weed fields, so my pond gets yucky, but my big bog just keeps chugging along and cleaning it all out.

Good Luck!

 

[brandonsdad02]

I added a UV light to my pond set up and did the quilt batting. Its takes about a week to start seeing a difference, but it does work. Think about how much algae it took to turn your water green. Now try running all that water over and over thru a small area to try and filter out the really fine stuff. It took 9 days to clear my pond.

 

[addy1]

lol so does my bog, just keeps cleaning the pond.

 

[JayDogg]

Is there a rule-of-thumb for the size of a UV filter? Mine is pretty small (9 Watts I think) and I assume I need something bigger. My Savio skimmer is setup to house two large UV's, but those things are really expensive! Is anyone aware of a low-cost or DIY alternative?

I'd also like to know more about bogs. The perimeter of my pond is filled with gravel and a good portion of this is submerged. Would it be possible to convert this area into a bog? What would be required?

 

[JayDogg]

Oh, lovinglife... I have two filters:

1. I built a biological filter out of a 55-gallon drum. I found the design on these forums, but don't remember who should get credit. The water flows in through a pipe from the top that swirls at the bottom (the settling area). Above that a shelf made from light grate supports a whole bunch of plastic bird fencing (the bacteria habitat). Above that is another light grate and a bulkhead where the water flows out of the filter. I also recently "planted" a bunch of mint (not water mint) in the upper grate. I'm sure it's not doing much filtering, but it smells good and is actually starting to grow really well. Only a portion of my 3500 GPH goes through this filter; I'd say 750-1000 GPH at most.
2. I filled the 30 gallon weir of my waterfall with small scrubby pads. Actually, I used a light grate to build a shelf in it as well. The water flows in at the bottom then through the light grate, a blue air filter, and all the scrubbies, then through another light grate and out the top where a dozen or so water hyacinths live. The flow through this filter is much higher (probably 2500+ GPH), which I believe is too high for bacteria to really do work. So I guess this one is more like a big mechanical filter.

I do have another 55-gallon drum ready for use. I just haven't figured out how to use it best.

 

[lovinglife]

Good Luck!

 

[addy1]

Is there a rule-of-thumb for the size of a UV filter? Mine is pretty small (9 Watts I think) and I assume I need something bigger. My Savio skimmer is setup to house two large UV's, but those things are really expensive! Is anyone aware of a low-cost or DIY alternative?

I'd also like to know more about bogs. The perimeter of my pond is filled with gravel and a good portion of this is submerged. Would it be possible to convert this area into a bog? What would be required?

jaydog, here is some info I wrote up on bog building see if it helps you

https://www.gardenpondforum.com/topic/6894-bog-building/

 

[brandonsdad02]

Jaydog, check in the DIY section and look for UV light build.

 

[Waterbug]

Filters do specific things. For some reason in water gardening a "bio filter" is assumed to do everything.

Proper sized and installed UV clears green water in 3-5 days. Manufacturer specs pond size and pump flow rate. Many water gardeners seem to like to ignore what the manufacturers says and just waste their money. Keep in mind the spec are for the maximum. Like if it says 1000 gals, don't expect it to work in a 1100 gal pond. Stay away from combo UV as the other parts of the filter can inhibit the UV. Keep it simple.

Using quilt batting to filter new bloom algae is like catching mosquitoes with a basketball net. You'll catch a few.

Clearing green water has nothing to do with nutrients. Test your green water for ammonia and nitrates. Zero ammonia and low or zero nitrates unless you really do have a runoff problem. The test will tell you. If the bloom continues nitrates will go to zero and you'll still have green water for weeks, months. Algae, like all plants, use nutrients to build new cells (reproduce), not as food. They don't starve without nutrients. When the water clears there will be an increase in nutrients, ammonia and nitrates. Hopefully bacteria will deal with the ammonia, but it is a danger that should be checked.

 

[crsublette]

Yeah WB, I know where your cards are probably always gonna lay on the nutrient vs. algae debate. I'm just gonna raise an eyebrow to that one.

Plants either grow foliage, roots, something, or they die back so they can grow again from roots, seed, spore, or something. Algae just "unexplainedly" collapse all of a sudden just does not sounds right. Definitely does not explain how algae can be so easily created with just lawn fertilizer or other nutrient pollution. If algae blooms are so easily created, then I wonder why is the reverse so tough to figure. It seems apparent the miscellaneous nutrients have to be in proper relationship; otherwise, another full blown algae presence would be reproduced when algae or any decay is present that overcomes the size of bacteria colonies and other enzymes. Algae is created in water for some kind of filtering purpose since they appear to be extremely efficient at consuming ammonia, nitrates, and other nutrients. Also, I bet algae of all sorts, string along with planktonic and others in the same water, they are there somewhere even though the human eye does not see it. I bet there is also ongoing growth that we are not able to measure nor witness with the human eye. I know this is going to be called a "logic trap", or however this wants to be dismissed; I just see far too much wiggle room either due to lack of explanation or lack of discovery in this arena for me to just outright ignore the entire nutrient vs. algae debate. My common sense radar tells me, with this much wiggle room, just does not sound right to say miscellaneous nutrients in proper relationship to each other plays absolutely zero role to algae's presence. I would need better persuasion for me just to outright ignore all this.

 

[Waterbug]

Persuasion? Yes, in forums persuasion is all that matters. Data, worthless. Links to studies, meaningless.