All my goldfish died suddenly

[Uncas2010]

SHORT VERSION: A tree has been dropping very small blossoms/seeds in and around the pond for 10 days. Cleaned them out regularly for 5 days. Then it rained for 5 days straight. I just went out to clean the pond and all (or at least most) fish are dead in the skimmer and the pond bottom and filter are almost clogged with mossy sludge and decomposing blossoms.

LONG VERSION: I have a small goldfish pond. The pond worked pretty well last year and all fish survived the winter and grew much larger (2 to 3"). This year, I drained and cleaned the pond thoroughly on April 5th. Some dried on crud remained on the walls, but I had completely removed the sludge on the bottom and cleaned it well. I did NOT use any chemical cleaners--just elbow grease. Dechlorinated immediately and returned the lilies to the pond. A few days later, I put the fish back in. They looked great and did well for 10 days. So I added some more 1" fish. All the fish seemed to be doing very well and the water appeared to be going through its natural cycle of developing healthy water profile. I also threw a Dunk in to keep the mosquitoes down.
About 10 days ago, an overhanging tree began to drop tiny flowers in the pond by the thousands. I skimmed the surface with a net and cleaned the skimmer filter a couple times a day and the fish seemed to be doing well, but the seeds continued to fall fast and in spite of the vigorous skimming, a lot of them had collected on the bottom.
5 days ago, it started raining hard and continued to rain until this morning. The skimmer and water fall filter were still flowing well. So I didn't clean the filters for the last 4 days. I just went out to clean the pond and all the fish were floating in the skimmer--even most or all of the ones that had survived the winter. There is no sign of animal attack. Fish bodies are fully intact with no abrasions. The skimmer and the filter are clogged with those tiny blossoms and a slippery, muddy, mossy stuff. The skimmer and waterfall were still flowing, but barely. The water is brown (a little tea colored, but mostly just muddy from all that rain). There are also a lot of those blossoms on the bottom decomposing quickly.
So please HELP ME. WHAT HAPPENED? Did those thousands of blossoms decomposing blossoms do something? Did the fish eat the blossoms? Did this huge amount of rain wash something into the pond from the mulch? I have pictures of the filters, but I can't figure out how to put them here.

POND DESCRIPTION: 900 gallon goldfish pond with 2 hardy lilies and japanese box snails. The pond is surrounded by rocks and fresh, hardwood mulch and a few plants (marigolds, lavender and citronella). No rocks on the bottom. No added chemicals except one Dunk added about 3 weeks ago. I do not feed the fish.

 

[MitchM]

To put pictures on here, once you have the picture on your computer desktop, click and drag it into the same box that you type your reply.

You may have cleaned your pond too thoroughly and started a cycle again. Did you measure the ammonia after you refilled the pond?
What type of tree(s) are dropping leaves and blossoms into the pond?
How many fish are we talking about here?

 

[addy1]

Welcome to our group!

Was the pond up and running when the tree dropped the stuff last year?

 

[Uncas2010]

To put pictures on here, once you have the picture on your computer desktop, click and drag it into the same box that you type your reply.

You may have cleaned your pond too thoroughly and started a cycle again. Did you measure the ammonia after you refilled the pond?
What type of tree(s) are dropping leaves and blossoms into the pond?
How many fish are we talking about here?

I appreciate your response Mitch. I cleaned all the sludge out of the bottom of the pond pretty thoroughly, but I didn't scrub the liner clean and I didn't use any chemicals. I was assuming that the pond water had started a cycle again, but would that harm the fish? The pond had 16 fish, but 9 of them are only 1" long. 7 of them are 2 to 3" long. So I don't think the pond is tremendously overstocked. The ammonia NH3/NH4+ is somewhere between .5 PPM and 1.0 PPM. As to the tree, I cannot figure out what it is, but there is a picture attached. Those leaves are about 2.5 inches long and the buds are less than 1/4 inch around. Thousands of them dropped into the pond every day. They didn't float long and most of them wound up decomposing quickly on the bottom of the pond.

 

[bettasngoldfish]

Did you quarantine the new fish prior to adding them to the pond? If not, there is always a risk of introducing parasites and or infections.

I wonder if all the rain messed with the ph. Did you happen to test your water?

 

[Uncas2010]

Welcome to our group!

Was the pond up and running when the tree dropped the stuff last year?

Addy, No the pond was not really up and running last spring. I moved into this house just about exactly 1 year ago. The pond had been in the back yard for a long time (probably 20 years or more), but the previous owner had grown quite old and the pond had been neglected for a few years. There was no functional filtration system present. The water was a dark tea color. There were small tree limbs and sticks and over a foot of sludge in the bottom. The realtor (who is a friend of mine) had thrown a couple dozen rosies in the pond in April, but I couldn't see any of them. I drained the pond last June and shoveled out most of the sludge, but I was really scared of damaging the liner. So I left a lot of muck in there. I installed a skimmer and waterfall filter system with a 1000 gps pump and a series of Matala low, medium and high density filters. Even with most of the sludge removed, the fresh water fill and new filtration system, the tea color remained and I spent the next couple months dealing with the water clarity with activated carbon.

 

[Tula]

Welcome to our pond forum. I'm very sorry about the loss of your fish If your ammonia is .5 - 1., that is high. Additionally, organics ( tree leaves / seeds) decaying on the bottom of your pond raises ammonia. If the pumps were clogged, the water circulation was reduced, resulting in less oxygen. I'm not an expert, but I think the fish suffered gill damage from ammonia and there was also low level of oxygen in the water. If you had a lot of rain, it could have affected your PH, which can make ammonia more toxic.

It sounds like you've put a lot of effort into your pond, so hopefully you'll keep on ponding.

 

[michey1st]

Is there any possible way that can be a Mountain Laurel? If so, all parts of it are very poisonous. I could very well be wrong (please don't freak out!), but its a good idea to ID it just to be on the safe side. Mountain Laurels are, I believe, evergreen like Rhododendrons and bloom in the May-June timeframe.

Any plant ID experts out there?

 

[addy1]

Does it set fruit?

 

[Dave 54]

It could be a number of factors the seeds and blossoms of your tree may be the smoking gun but with the rain you have had I'd say it may have something to do with run off into your pond
Could you tell us what the blossom is we do have two lists on site of plants and shrubs dangerous to fish but nothing really in the way of trees though

Dave

 

[Uncas2010]

A friend (fish tank master, but never had a pond) tells me that he doesn't think the tree had anything to do with it. He thinks it was the rain or the fact that my new water was probably only half way through the cycle. So I guess I will go get a liquid test kit tomorrow and see how things look. I guess the ammonia level and pH are the most likely causes.

 

[addy1]

The tree debris may have just pushed the water over the edge. Let us know what you find out.

 

[MitchM]

It looks ammonia could be the reason that your fish died, but the cycle should have been completed if the fish have been in there since then.
You refilled your pond April 5, but 8 weeks later they died?
Having positive ammonia readings after 8 weeks is not good.
It's too bad you don't have any ammonia readings from even a few weeks ago.
The decaying plant matter will contribute to ammonia levels, so I think addy is right that the falling blooms may have pushed the water conditions over the edge for the fish to survive.

You said that you left some of the sludge on the bottom when you first cleaned it. It probably would have been better to remove it all at that time. Depends on how much you left in.
If this was my pond, and there were no longer any fish, I would consider cleaning out the pond completely and start over, but get a master freshwater test kit form API and monitor the water conditions as you go.
Could you post a picture of the pond itself plus what filtration setup you have?

 

[Uncas2010]

Mitch, excuse me, I mis-spoke. I cleaned the pond on May 5. Not April 5. And I did clean it entirely. No sludge remaining in the bottom this year. So I have positive ammonia readings at 4 weeks, not 8. I didn't understand that the water cycling would harm the fish. I thought it only related to water clarity. Huge mistake, but now I understand.
Anyway... I bought a liquid test kit. This morning I had the following results:
pH 7.0
ammonia 1.0
nitrite 0
phosphate 2.0
*** tap water is also 2.0 phosphate
I am confident that the water is still cycling and I am assuming that is the source of the ammonia readings.
Here is what I've done today:
1. Added 8 pounds of salt (I know this is controversial and there are wide ranging opinions, but I did it)
2. Added 8 ounces of bacteria boost
3. Added 10 bunches of anacharis (to the 2 hardy lilies already in there)
4. Bought 8 sacrificial goldfish and quarantined them. In 2 days, I will give them a 0.3% salt bath and then return them to pond water quarantine. After the salt bath, I intend to add a couple to the pond every few days. Hopefully the water will be done cycling in another week or 2.
So now I've got the phosphate problem. It's in my water supply. So I need to do a little research to figure out how harmful it is at this level and what I can do about it.
And here is a picture of my pond with it's dark water. There's a bio filter in the waterfall with 3 grades of matala.

 

[Tula]

I think salt might harm your water plants. I like the shape of your pond , looks a little heart shaped