To crayfish or not to crayfish?

[myswtsins]

I have a 30ft stream. It gets crazy algae!

The root problem? I dunno. I do not feed my fish anymore, the pond is only 1 yr old so there cant be too much accumulated stuff, I have pretty good filtration and when I clean the rocks in the stream (every spring and fall) there isn't much gunk in there. There is a lot of sunlight and I have planted a tree that will provide the stream some shade in a couple years but for now.....

In the main pond the fish keep the algae completely in check but up in the stream there are no fish to eat it. I would like to add some life to stream just for the heck of it anyways so I am thinking maybe crayfish could help with the algae issue as a bonus. Opinions?

I don't have any plants besides lilies IN the water, they are in in plant pockets (you can see one on the left and one on the right in the bottom picture there) so I am not worried about them eating my plants so much. I know that they won't stay where I put them necessarily but considering the stream is the most ideal place for them to live they might hang out there anyways? Knowing that they probably can't survive the winter here I know I would need to catch them and bring them.

What else should I consider? As in regards to crayfish and in regards to other options for life and/or algae control.

 

[Meyer Jordan]

Test the Phosphorus (and Nitrate) level of the water. Controlling the nutrient load is the first step to controlling algae.
Crayfish are omnivorous, but require Calcium in their diet.

 

[myswtsins]

Thanks for your suggestion. I have done many tests, with liquid tests. 0-0-10 is the highest i've ever had with 0 phosphates. I have tested the test kit too. I have aquariums where all of the above show up. Besides any possible phosphates being released by the muck in the rocks is used up by the algae before I would be able to get a reading. I have started threads on the problem before and have tried everything recommended with no success. I am trying patience and a little shade now, fingers crossed.

I didn't make this clear above....I am more interested in adding crayfish for personal stimulation then for algae control, just figured that might be a bonus. And looking for more opinions on the matter.

*Edit- As for the calcium part, the millions of pond snails I have would provide that for them right?

 

[Meyer Jordan]

Have you tried PhosOut of PhosLoc? Can you restate the Phosphorus level as a decimal value?

Easy to test Calcium level. API makes a test kit for this.

 

[myswtsins]

I have not used any chemicals or additives and will do everything possible to keep it that way unless I REALLY have to. Not saying they don't have their place but looking at the algae isn't THAT bad for me. Phos level is 0.0 not even a tenth of a point and that is multiple tests that show that.

Oh, you're talking free floating calcium not eaten calcium. I have found calcium test kits to be fairly unreliable, but I do know my water is fairly hard in general and chances are that it is not only magnesium and other minerals. I can keep African rift lake cichlids (with minimal added hardeners) and snails and such without trouble. Last test was kh-6, gh-4 which is typical of my test for this pond.

 

[Meyer Jordan]

I have not used any chemicals or additives and will do everything possible to keep it that way unless I REALLY have to. Not saying they don't have their place but looking at the algae isn't THAT bad for me. Phos level is 0.0 not even a tenth of a point and that is multiple tests that show that.

Oh, you're talking free floating calcium not eaten calcium. I have found calcium test kits to be fairly unreliable, but I do know my water is fairly hard in general and chances are that it is not only magnesium and other minerals. I can keep African rift lake cichlids (with minimal added hardeners) and snails and such without trouble. Last test was kh-6, gh-4 which is typical of my test for this pond.

A Phosphorus level greater than 0.005 mg/L will support a filamentous algae bloom. A little goes a long way.

If you have a healthy population of snails then it is likely the Calcium level is high enough.

 

[pecan]

Can you set up a shade sail over the stream? Shade really helps reduce algae. Once your tree grows enough to shade the stream that should help, but then you will be digging all the tree debri out of the stream so its kind of trade off. Dont know much about crawdads, so I cant give any advise there.

 

[MitchM]

myswtsins, you say you don't have any plants, but you do....algae.
Your water is telling you something.
Have you tested your source water? Do you have leaves falling in the pond? Plant debris - falling leaves, lawn cuttings would add phosphorus.
That algae is helping keep your pond water safe for the fish, by the way.
I hope you're not doing water changes....
Try adding some more plants to suck up the nutrients that the algae is feeding off of.
In the meantime, harvest the algae and put it in your garden.

 

[myswtsins]

A Phosphorus level greater than 0.005 mg/L will support a filamentous algae bloom. A little goes a long way.

If you have a healthy population of snails then it is likely the Calcium level is high enough.

My API test goes from 0.0 to 0.25 mg/l so I can't test down to 0.005.

When I stopped feeding the fish, as directed by members here to do to fight the algae, my plants suffered, a lot, but the algae did not. In my experience with planted tanks limiting/eliminating macro nutrients (Nitrogen, phosphorus and potassium) had the same effect, plants suffer but the algae remains. Algae can use nutrients in the smallest amounts and in several different forms so when you try to remove the nutrient to fight the algae now the plants can't find it or use it but the algae still can just worsening the situation. Best solution I found with my planted tanks was to reduce the light

I tried the suggestions against my own desires to interact with the fish (feeding) and besides the fact that what I stated above as my own experience because this is an outdoor pond with mostly emergent growth which I had no experience with but it had the opposite desired effect. Next year I will try resuming feeding but add more shade.

Can you set up a shade sail over the stream? Shade really helps reduce algae. Once your tree grows enough to shade the stream that should help, but then you will be digging all the tree debri out of the stream so its kind of trade off. Dont know much about crawdads, so I cant give any advise there.

I agree. I will be setting up something till the tree has grown, a shade sail or umbrella or something of my own creation. The pond is surrounded by trees as it so I am accustom to the tree debris but the tree is actually a fair distance from the stream itself. Thank you for your suggestion!

myswtsins, you say you don't have any plants, but you do....algae.
Your water is telling you something.
Have you tested your source water? Do you have leaves falling in the pond? Plant debris - falling leaves, lawn cuttings would add phosphorus.
That algae is helping keep your pond water safe for the fish, by the way.
I hope you're not doing water changes....
Try adding some more plants to suck up the nutrients that the algae is feeding off of.
In the meantime, harvest the algae and put it in your garden.

True, algae is a tiny simple plant! I meant I had no plants IN the water for the crayfish to chow down on. I have TONS of plants that feed off the pond water tho including a 12'x3' bog/veggie filter.
With the way I have it setup almost every leaf makes it to the skimmer before sinking. No lawn area near by, on purpose, transitioned it all the hardscape with the pond in mind.
Algae is good for the water, I know. I just get tired of looking at it. lol
No water changes besides the natural ones that occur when the pond (actually the water reservoir) overflows.
And I do harvest it and put it into the garden or compost! I like the way you think! Thank you for input!

 

[peter hillman]

You'd need a 10lb lobster to eat all that!

 

[myswtsins]

I'm ok with that too! Better eating at the end of the season!

 

[MitchM]

Have you checked to ensure that your pond isn't getting any surface runoff running into it?
Your pond doesn't look like it has much of a berm to prevent that.

 

[Faebinder]

I'm interested in putting a crayfish in my pond. Anyone have a specific type that they recommend that could survive the winter? I got goldfish, so I'd want one that doesn't go after my fancy goldfish.

 

[Lisak1]

I can't add much to the discussion except to say we put four crayfish in our pond (@Faebinder - not sure what kind? Bought them at the same place we bought our koi) and we've seen them a handful of times since then. Make that less than a handful... maybe three sightings, total over five years time. I would have thought they were all dead except we saw one again last summer. I think they probably stay hidden in the rocks in the pond. Like you @myswtsins I wondered if they would survive the winter - we are zone 5 - but obviously they did. I would say your chances of catching them once you release them are slim to none. They are elusive little critters. As for eating the algae - not sure how effective that would be, unless you had an army of them.

I would suggest you try some watercress in your stream. Just buy it from your local grocery store - it's generally sold in bundles in the fruit/vegetable section. It doesn't need to have roots. Pull the bundle apart into stems and tuck a few stems every few feet into the rocks at the sides of your stream. Within a matter of days it will start growing - watercress LOVES flowing water. It's one of the best water filtering plants I've found. You have to watch it because the roots grow into massive mats that will collect loads of silt and debris. If it gets too thick, it will divert the water, possibly out of the stream. I pull out pounds of it every few weeks from my waterfall all summer long - it's amazing stuff. We add it to salads or juice it with other greens. Very healthy for you! Ours will even occasionally come back the next year if I leave a few clumps of it in the fall. But even if I have to replant it, it's a $2 investment every spring.

It's also really pretty - here's a picture of my waterfall:

See the sunbathing mermaid? Over her head and to the left of her is all watercress. Scale is a bit tough to tell - she's about 20 inches tall. There's a small pool behind all that cress fed by both the bog to the left and the small stream directly behind it. I had already pulled a lot of watercress out - it was slowing the path of the outlet from the bog causing a bit of overflow.

Completely off your crayfish topic I know, but hopefully another idea for you!

 

[MitchM]

myswtins, your algae has a vibrant green colour to it for someone that is not feeding the fish anymore. The nutrients to feed the algae have to be coming from somewhere.
Did you figure out what the oily residue was on the rocks?
The various containers you have that you submerged, what did they originally contain?