uh oh ..

[swamp creek farms]

since the growing season is out, I thought my fish might want some fresh water. So I drained the tank and put fresh water back in it. It was clear and fine before I messed with it. Now I have green water. I thought it was just algae so i wrapped black plastic around the tank. Still not back to normal - about two weeks now. Any ideas on how I can see my fish again ?

Don't fix what is not broken.

[rfeiller]

The algae is helping cycle the tank. Let the algae do its job
Green water I'd great for the fish. It will clear on it's own. They is nothing better for your water then algae, it removes ammonia.

[keith_r]

and make sure you add air, the algae is consuming oxygen as well

[urbanfarmer]

and make sure you take off the plastic, the algae needs sunlight too

[JCO]

As Keith_r said :

the algae is consuming oxygen

Additionally, some algae also secretes toxins to inhibit other algae from growing and those toxins in mega loads can damage fish gills and the fish will suffocate. Take it from the voice of experience...I lost almost $1,000. worth of 18" Koi this year before I could get control of it in the Koi pond. Waiting on it to clear proved fatal to the Koi and my wallet because they were due to spawn in the spring. Go to the pet store and get a commercial pond algae killer and dose the tank as directed. I would much rather have clear water than dead fish.

[urbanfarmer]

As Keith_r said :

the algae is consuming oxygen

Additionally, some algae also secretes toxins to inhibit other algae from growing and those toxins in mega loads can damage fish gills and the fish will suffocate. Take it from the voice of experience...I lost almost $1,000. worth of 18" Koi this year before I could get control of it in the Koi pond. Waiting on it to clear proved fatal to the Koi and my wallet because they were due to spawn in the spring. Go to the pet store and get a commercial pond algae killer and dose the tank as directed. I would much rather have clear water than dead fish.

Well, I without a doubt learned something new today. There is an algae that releases toxins (not to stunt growth), but I would not use an algaecide in your system on this information alone... it appears this algae is called Karlodinium veneficum and can be harmful to the fish in high concentrations under the right conditions.

K. veneficum is a mixotroph, meaning, it can feed on microalgal prey when inorganic nutrients (such as nitrogen and phosphorus) are low, which is the only time it releases this toxin. It has been associated with fish kills in finfish aquaculture ponds as well as in estuarine waters. The toxicity is low as it takes 48 hours at concentrations of >100 million cells per liter to kill cod larvae.

You will most likely not have to worry about it in most aquaponic systems with adequate plant nutrients since the algae only releases the toxin when it is hunting microalgal prey because it can't get what it needs directly from the water. I am basing this conclusion off a recent discovery this year, see: http://www.sciencedaily.com/releases...0121140342.htm


Great summary info on K. veneficum
http://research.myfwc.com/engine/dow...dltype=article

A study on the distribution of K. veneficum along the US East Coast.
http://plankt.oxfordjournals.org/con...8/905.full.pdf

[BELOW ARE MY THOUGHT PROVOKING, YET UNSUBSTANTIATED CONCLUSIONS]
Tilapia are hardy fish and may even have a natural resistance to the toxin... Tilapia EAT these guys anyway... Koi probably have a lower tolerance to toxins in general... HOWEVER, I wonder if this might be the REAL reason Tilapia grow slower in green-water aquaculture... because they are dealing with the liver and neural toxins released by this algae... perhaps that is why they grow FASTER in green-water aquaculture WHEN supplementally fed on commercial feed BECAUSE the phosphorous and nitrogen concentrations in the water are maintained at levels that keep the K. veneficum from releasing the toxins!!! This makes sense to me because Tilapia are supposed to convert algae into body mass far more efficiently than commercial feed, yet Tilapia tend to grow slower in pure algae aquaculture compared to pure commercial feed aquaculture. Moreover, we all know Tilapia try hard to survive in bad water conditions, but they do so at some cost like growth. So, I think this stands to reason, but I would love to see some scientific studies on it... the implications are huge, but I don't have the resources to conduct such a study. Someone PM me when they have done it or find such a study.

@JCO
I don't know jack-diddly about Koi, but I did see on a YouTube video of a Koi farm: the lady said that the Koi actually have less stress in algae water (because they feel safer in the murk) and develop better color in that kind of water (she didn't say why). Anyway, just a thought...

I doubt your fish died from this species of algae releasing toxins into your water... there would have to be a very high concentration of this algae, and it doesn't exist in every body of water... and if it is present, it is usually in balance with the other microorganisms.

However, assuming your fish died due to toxins from this algae, my only guess is that you were trying to keep the water SO CLEAN, you removed the vital nutrients this algae needs and made it switch into "kill mode"; thus, killing your fish. You would have done it to yourself, man!

Regardless, your sacrifice will not go in vain because it has taught us all a valuable lesson!!!

[JCO]

I don't know jack-diddly about Koi, but I did see on a YouTube video of a Koi farm: the lady said that the Koi actually have less stress in algae water (because they feel safer in the murk) and develop better color in that kind of water (she didn't say why). Anyway, just a thought...

I doubt your fish died from this species of algae releasing toxins into your water... there would have to be a very high concentration of this algae, and it doesn't exist in every body of water... and if it is present, it is usually in balance with the other microorganisms.

However, assuming your fish died due to toxins from this algae, my only guess is that you were trying to keep the water SO CLEAN, you removed the vital nutrients this algae needs and made it switch into "kill mode"; thus, killing your fish. You would have done it to yourself, man!

First off, I don't know who the lady you speak of is, but that is irrelevant because I have been raising KOI, both standard and Butterfly since 1965. I have raised and sold thousands upon thousands over the years and yes it was my fault as you will read. I did not heed the warning.

Now a point of fact: KOI kept in murky water do no better than KOI in clean water color wise or health wise. The Japanese have proven that because they keep their KOI ponds crystal clear and pride themselves in doing so. For a Japanese KOI keeper to allow his KOI pond to become merky or polluted is a complete disgrace. Additionally, KOI adapt to the clear water with no problem and become so tame to the site of you, they rush to the feeding spot every time you approach as if they were the little pigs they are.....therefore...no stress.

DID NOT HEED: As for the reason my fish died wasn't because I keep the water clear because I don't filter it or circulate it. Their pond was and is of sufficient size that, that is not necessary. The problem was caused by the St. Johns river which flows through North East Florida and is less than two miles from me. What say you, could that have to do with anything? This spring the St. Johns, as it does each spring, had a tremendous algae bloom which killed finned fish by the thousands and the fish and wild life persons warned that spores carried by the wind could cause problems in aquaculture ponds.

Since my pond already had algae in it, I thought nothing about it until the morning I went out to feed them and they were all at the surface gasping for air. I had a 150 gal stock tank close by that had a cover on it to hold replacement water for my aquariums so I immediately started trying to net them out. I caught the biggest ones first and the first one I caught and placed in the stock immediately stained the water with blood from her gills as did the rest. They were all dead by the next morning even with clean water which was being filtered. None survived. Their gills were so damaged by the time I realized there was a problem there was nothing I could do.

So yes, I did kill them by not putting an algaecide in the pond shortly after the fish and wildlife warning was issued. What was the name of the algae...I don't know but it happens each spring in the St. Johns river and that river is a long way from being crystal clear.

[urbanfarmer]

Hm, yes you are right that does sound exactly like Karlodinium veneficum. My only reason was that under normal situations it is highly unlikely that this algae can gain access to your closed system, but as you mentioned you were close to a body of water that in fact contained the little bugger. I'm sorry for your loss, I know I would be upset too...

As far as the Koi, thank you for "clarifying" the situation. (Are all my jokes this bad?) Anyway, I really know nothing about Koi as I said, but I welcome the knowledge from an experienced and knowledgeable Koi cultivator.

[rfeiller]

sorry about your loss. remind me not to move to florida, how tragic.

how could you possibly avoid the disaster?

[JCO]

Should have added algaecide when the warning was televised. It's called paying attention to details and that time I didn't