Backyard Aquaponics
A place to discuss aquaponics

Morning all,
I have issues in my systems (running for about 3 weeks) with algae blocking the holes in the irrigation pipe.
I am currently cycling with no fish or plants (bacterial starter and fish food in the water) and was wondering whether this is likely to stop once the plants go in and start using up the nutrients?
I've seen stuff for aquariums that you add to the water to get rid of algae but I can't find out exactly how it works. Just wondered if anyone knew what these products do and whether they'll be likely to inhibit the growth of other plants.
Cheers,
Neal

For ponds with no fish i belive it is a algaecide. Would not be a good idea to use this.

For aquariums and ponds with fish i believe it is called a "flocculant". The alage is usually ultra small in size, easily passing through filters. A flocculant makes it clump together, and either sink to the bottom or be able to be filtered.

Neal i found this problem with my 6mm holes as well, but i have found that increasing the flow rate so that they don't get a chance to clog help out heaps.

Steve

Steve, does a UV light clarifyer made for ponds help?

I believe it would, but they are expensive to buy, expensive to run, expensive to replace bulbs and kill every micro org. in the water.

didn't mean to be so negatve

Thats ok, I have been looking at Pond supplies and was not sure if this would be an answer. I know that algae is a major factor. With the Florida sun I have found this to over run quickly. This a good subject to find an answer to.

Thanks everyone,

I don't think a flocculant would be very desirable as lumps could form in the pipe and cause greater problems. I have 6 setup's running, so UV clarifiers could break the university bank! Thinking about Joyce's point on sunlight, once the plants go in, the irrigation hose should be shaded somewhat by the leaves anyway, which will hopefully reduce the problem.

I covered the tanks with shading material yesterday as well so that should go some way to reducing algae in the tanks themselves.

I'm assuming the algae is utilising much the same compounds as my crop needs, so it will be 'robbing' my lettuces of nutrients when they go in. Is this a fair assumption? I suppose periodic unblocking of holes and tank scraping is the only real solution.

Algae blooms are typical of newly established systems. I had long filamentous algae oh, 2 years ago. Once it left it never returned, it's present in the system, just minimised as things balanced out so now it's 5 mm as opposed to 2 inches.

Algae eaters are good and well till they can actually get lost in the forest of algae.

Six set-ups. Nice. But I know nothing about them, what parameters did you follow in construction? 2:1? 1:2:4? Can't help with system specific quirks or possible environmental inputs you'd not thought of without knowing what you're actually doing...

I switched to recirculation systems upon viewing my forests of algae. The increased water did slow it down. But time was the real winner.

I say you are seeing the typical new system bloom and it will go away. But have no info to qualify this.

Oh, AA i just realised that i didn't clarify my algae inmy system, and which may have led you to believe it was very new. its not filamentous at all, more like just green water, much like in many peoples pics.

Hi AA,

They're only small systems, 6/7 lettuce plants + 8 goldfish in 70l of water in an expanded clay substrate gutter system. Unfortunately it's only a short third year degree project.

I did post a full description in another topic-
http://backyardaquaponics.com/forum/viewtopic.php?t=103 some time ago and there's a picture in the systems album too http://backyardaquaponics.com/forum/alb ... ?pic_id=48.

I am recirculating but the width of the gutters i'm using means the flow rates have to be quite slow or else the water shoots over the top.

I'm familiar with the algal bloom from reading other posts, is it something that happens in every system then? I have limited experience of fish keeping but I assume you don't get this problem so badly in aquaria because of the low light levels indoors. If that's true, is it fair to assume shading the tanks and covering the growing channels with plastic to exclude light (planting through the plastic into the media) could minimise the growth of algae?

Cheers,
Neal

I tried everything except an expensive UV filter. Only time really fixed it.

That is a lot of light exposure to the clay medium. Shade will always help but it wont win this particular war, only patience will.

How long do you have to go on your study? It will improve.

Steve - water green huh. Your carbon probably stripped all your lignin cracking enzymes leaving you prone to green water till they repopulate. Unlike most bacteria, these fellas like to work in the water column where the algae arrive... The algae is definately contributing to your pH yoyo.

A bunch of daphnia would consume a lot of it and make it more bio-available for your fish to uptake and then the bacteria can redistribute it in a more well balanced manner. However, how the hell are daphnia gonna survive in a tank of fish?

In a mesh holder! Hehe.

Second thoughts, the daphnia are very sensitive, they may die too lol.

How big are the holes in your pipe that are getting blocked Neal? When the pump is turned down to a very slow rate, then small pieces of fish poo/feed/algae can get blocked in the holes. I have this problem on one of my very small systems and I have to keep tapping the pipes to try and dislodge the muck caught in the holes.. My other systems never have any problems as they have larger holes in the pipe....

You will have some algae in your system, can't escape it with nutrient rich water, are the holes in your pipe pointing down into the gravel, this is important to stop algal growth. And I'd drill your holes out a little larger.

AA, carbon was in the inside tank, not the outside one

EB, i have also progresivly raised the level of the clay balls to cover the pvc water distribution pipe...........I tend to want to try things for myself sometimes, but you were right.

Thanks everyone,

I'll change the configuration so the holes are pointing down, make them larger and increase the flow rate.

The fish go in tomorrow and the lettuce plants in 2 weeks' time after the nutrients have had time to build up.

The project will probably run until November, hopefully allowing for at least 2 crops in each replicate. The lettuces are transplants in rockwool cubes sourced from a commercial grower, who is also providing the nutrient solution recipe for a standard hydroponic system running as a comparison.

I know the aquaponic systems probably need more time to establish but it's all I can do with the time I have. Hopefully I can do a more in-depth trial in the future!

Cheers,
Neal