Blue-Green Algae.

[wey2go]

Hi! My pond (was swimming pool) was green even before rainbow trouts were introduced.

Concern now is if I am to eat the trout, how do I know that it is safe to eat them? Somebody warned me of the blue-green algae (Cynobacteria Algae) which can be toxic.

[wey2go]

Sorry, I should not have posted this thread here.

[GaryD]

Hi Wey2go,

Don't worry, I'll remove the thread when you've found out what you need to know.

What makes you think that the green stuff in your pool is blue-green algae?

Most aquaponics systems will go through a pea soup phase on their way to maturity. I think I can recall you saying elsewhere that you'd been overfeeding.....this may be the reason for your algal bloom.

Gary

[wey2go]

Gary,

Thanks.

The pool was already green and thick pea soup before fish (rainbow trouts) were introduced. So, I think it is not a matter of overfeeding. It was an existing problem before fish came along.

I started thinking about blue-green algae after emailing with Joe from www.duckweed.com.au. He mentioned about not letting pets or children near the pond unless I am sure about no blue-green algae. By the way, he charges $120 plus shipping for his "Duckweed Kit".

Then I started reading more about blue-green algae. One of the symptoms is itchiness of skin in contact with water with blue-green algae. Skin on my shin has been itchy lately. But of course, it may be mere co-incidence as I suffer from hay-hever and apart from sneezing, I get skin irritation. Also, I did noticed occasional greaser kind of floating stuff on the surface of the water.

I am now trying to find ways to quickly improve the condition of the water in the pool. 2 weeks ago, visibility was under 6 inches (cannot see my finger tip if I put my hand into the water past 6 inches). After 2 weeks of running 2 pumps (16,000 lph and 6,000 lph) and one of them through a 72W UVC, visibility has improved to about 2 feet.

Also, started running water through an OASE Biotec 18 pond filter (rated for up to 40,000 Lt pond with fish and my pond is about 30,000 Lt) last Thursday. It will take time for the filter to start doing its job.

I have been manually scooping out floating clumps of algae from the surface almost on a daily basis since running the UVC.

I have been looking locally for Duckweed and found them in my local Bunnings store (as a "by-product" of Water Lettuce). They sell the Water Lettuce and not the Duckweed (both type Azolla and the other one, roundish/oval small leaf). Got some from them but very small quantity. So, need to get them to multiply really quickly now.

Also, problem with salt in the pool water (was a salt-water chlorinator pool). Duckweed may not grow properly in there.

[GaryD]

Hi Wey2go,

What do you get for the $120.00?

Gary

[wey2go]

This is what I got from his email. I have not asked more as I think $120 is quite a lot to pay for Duckweed. :)

Quoting Joe &/or Kerrie Baker <jkagencies@gmail.com>:

> Hullo Wey
> You need to .live in Australia, then I can send it to you, I have two
> species Lemna Desperma and Lemna Landoltia I recomend Landoltia as it has a
> slightly larger frond, if you tell me what you want it for I can probably
> advise further.
> It will cost $120 plus postage.gets you advice notes, duckweed & and
> fertiliser as you establish it
>
> Give me your home phone and I shall call you, I get charged too much when I
> call mobiles
>
> Regards Joe

[mikkey]

Does anybody know what type of salts and the amounts you can put in an aquaponics system to prevent or slow down algae?

[fishfood]

Hi salt wont slow down algie you need to shade the fish tanks

[nick]

the only other thing that I have heard that has an effect on algae is barley straw. For your size pool/pond get a couple of bales and put them on the step. As they break down they excrete substances which inhibit the growth of algae,
CHeers Nick

[Dufflight]

Once your system cycles the aglae naturaly goes away. It hits a critical mass and dies off. It takes some work in keeping an aglae bloom going when breeding fish. I don't even worry if my system goes green after rain. A few weeks and it goes back to clear again. I can speed it up with a filter.

$120 for duckweed you can get for free in most places. And the special fertiliser is any ammonia source. Fish is a good one.

[wey2go]

Don't use Barley straw if you want your water nice and clear. I tried it and my pond water has permanent tea-colour to it now.

Best to properly cycle and filter your water. A balanced system is much better than putting lots of unnecessary stuffs.

[Pseudoreality]

Don't use Barley straw if you want your water nice and clear. I tried it and my pond water has permanent tea-colour to it now.

Best to properly cycle and filter your water. A balanced system is much better than putting lots of unnecessary stuffs.

I know this is an old post, but I'm wondering what people's thoughts and experiences are with barley straw? I used it in my tank after an algae bloom and now my water is crystal clear. However, I have sky high nitrites that are probably because of the algae die-off, but it could be related to the barley straw. I also added a bit of pond clear (coagulant). Now my water is clear, but my plants are sad and my nitrites just don't want to come down.

[Ravnis]

You get 3 phase ammonia from the barley straw. The straw releases some as it decomposes, the ammonia load that was going to the algae no has to go to the bacteria. The dead algae decomposing supplies ammonia. The ammonia converting bacteria grow fast and will soon keep up, the nitrite converting bacteria will take 5-10 times longer.

[Pseudoreality]

Thanks Ravnis, that's pretty much what I assumed was going on. I guess the only question now is do I remove the barley straw or not? I'm not sure how much ammonia load its providing the system. Some research I've done online states it has other beneficial properties that help fish. The fish seem to be tolerating the high nitrites and I don't want to disturb things too much (other than bringing the nitrites down).

[Ravnis]

I know that others report that it works well. The nitrite converting bacteria just need time to catch up. If it was me I would just leave it and monitor. I would not expect nitrites to start coming down for 24 - 48 hours.

[pki]

My first system, after i gave it a pretty good dose of EM, [essential micronutrients] developed a blue green algae, that after I tasted , said pretty good, I was warned it could be bad, don't eat more. Had trouble getting rid of that. Duff what type filter do you use to filter algae?

[keith_r]

i see more people trying pond solutions in ap systems.. ponds are a complete system (even though some fish farmers feed, to increase fish size-
many additives that work great for ponds are not applicable to ap and some can even cause pretty bad results..
as you saw, the barley straw helped with the algae, but caused other problems.. nitrite poisining can cause lots of fish problems (brown blood disease being the major one)
pond dye (used to kill aquatic plants etc) will kill your gb's, the dye is meant to inhibit photosynthesis..
the common, easy solution to algae problems is to remove the light source from your ft, and add aeration.. after the initial algae bloom dies off, the dying algae creates a chemical that inhibits future algae problems..
the only thing an ap system really needs, is water, fish, quality fish food, plants and media,, and lots of patience!

[Pugo]

the only thing an ap system really needs, is water, fish, quality fish food, plants and media,, and lots of patience!
That was perfect, and pure truth.. and the part about patience was spot on, everyone seems to be in the instant fix mode. Trying to get everything perfect by adding stuff.. and spend all there time fighting the system instead of just letting the system balance itself.

[Pseudoreality]

i see more people trying pond solutions in ap systems.. ponds are a complete system (even though some fish farmers feed, to increase fish size-
many additives that work great for ponds are not applicable to ap and some can even cause pretty bad results..
as you saw, the barley straw helped with the algae, but caused other problems.. nitrite poisining can cause lots of fish problems (brown blood disease being the major one)
pond dye (used to kill aquatic plants etc) will kill your gb's, the dye is meant to inhibit photosynthesis..
the common, easy solution to algae problems is to remove the light source from your ft, and add aeration.. after the initial algae bloom dies off, the dying algae creates a chemical that inhibits future algae problems..
the only thing an ap system really needs, is water, fish, quality fish food, plants and media,, and lots of patience!

I would like to counter point a bit, if I may. From my understanding fish are generally the more sensitive organism in aquaponic systems. Therefore, some hydroponic methods are not always appropriate and can hurt the fish (i.e. rapid pH changes, certain nutrient solutions, pesticides, etc.). However, many pond solutions are harmless to plants and may be acceptable for aquaponic systems. Many ponds have plants features and when you read pond books they talk about fish and plant health. Nitrite poising is just as bad for fish in aquaponic systems as ponds without plants. Therefore, I don't think I was horribly in error by trying the barely straw pond solution in my aquaponic system. If adding barely straw typically caused toxic nitrite poising to a point where you see fish deaths it would not be so commonly recommended for pond use.

[Pseudoreality]

That was perfect, and pure truth.. and the part about patience was spot on, everyone seems to be in the instant fix mode. Trying to get everything perfect by adding stuff.. and spend all there time fighting the system instead of just letting the system balance itself.

In general I agree with you. Biological systems need time to balance. However, I have an extremely short growing season (3 months total) and sometimes need to use certain tricks to speed things up.

[keith_r]

i don't think you were horribly in errror.. i understand the short growing season for sure!
i've been reading more about ponds and such, and while there are some good ideas for ap, many things (like adding lime to raise ph, fertilizing a new pond to start algae bloom, then adding feeder fish then your predators over time to establish populations to make a pond more "self sustaining" are great for ponds..
i'm kind of working on my basement system, i may try to start a bloom in my large tank (almost 700 gallons), then add daphnia and scuds, then add minnows when the bloom starts to die off.. then add my perch (or trout or whatever i decide to grow out)
after the feeder fish are cleared out, i'll be using pellets, and maybe supplemental feeder fish i am working on raising (rosy red minnows)
so it's kind of like a pond, but usually you have fewer species..
i guess i'm saying just be careful with anything you add to an ap system..
you could cut your cycle time down if you over winter any fish indoors, squeeze your filters out into your gb's when you start your water flowing..