HI .

After following all the advice on the site and chatting to you , I have checked the ammonia and nitrite levels, perfect as ammonia is 0 for now , PH is 7
It been raiinng quite heavy in durban and for this whole week we have been exposed to load shedding twice a day .
I got up this mornig to a tragic site , one of my koi's and goldfish died .
The pump and filter went off last nite at around 12 for 2 hours .
I checked on them and they were fine.
Went to sleep and this mornig lights went off at 6 , when I went to check on them t 7 this mornig I discovered this tragic site .
Could this have something to do with the + - 4 hours that the filter waterfall and airstones are off per day . I really need to know as the pond is fine in terms of water quality.
Thanks
Devan

Hi,

it is difficult to tell what causes the death.

What is the size of your pond (liters)?
The amount of fish in the pond?
What is the volume of water turnover per day?


Pieter
http://southafricankoi.11.forumer.com

Hi Devan

Sorry to hear about your loss. As Pieter said, it is difficult to say what the causes are, especially if we do not know what your setup is.

Four hours without power should not be fatal, unless you are overstock, especially if the power went of at night time. (66.6 cm per 1000 liters) If the power goes off in the middle of a summer day, the effect is much worst. The colder the temperature, the longer the oxygen will stay in the water and the longer the fish can survive without filtration.

Another very relevant question, do you have a sand filter? The effect on a sand filter is often worst than the lack of oxygen in the pond. When the power goes off, there is no flow through the sand filter, and therefore no oxygen at all. During this stage, the pseudosomonas and aeromosomonas (bad bacteria) goes crazy in the sand filter and you beneficial bacteria dies due to the lack of oxygen. When the power goes on again, all the bad bacteria that was created inside the sand filter flows directly into the pond and cause havoc. Therefore you should always put the power switch to you pump off when the power fails, and open the lid of the sandfilter during the power outage. When it goes on again, replace the lid, put the system on backwash before you switch on the pump again, to get rid of the bad bacteria before you resume filtering. This is very important.

It is also a good idea to put your hosepipe in the pond during power outages(or at least after one hour). The outlet of the hose should be as high as possible, or create a small venturi for your hosepipe for use when the power fails. (Add a bit of anti chlorine unless your hosepipe is opened very small)

When I get a power outages, I run my borehole with a fairly small generator, and it provides new water and oxygen to all my 19 ponds at the same time, and it is no hassle. I purely start the generator and each pond is connected to the borehole and each outlet is fitted with a small DIY venturi. When the power goes on, I do a small backwash to flush my sand filters and to bring the water level back to normal.

HI Pieter/Paul

The pond is 3000 L with a 2500 L pump going through a UV light and filtered into one of those rectangualr black filters .
The media inside is 2 layers of course sponge and some of these rocks in a bag that form the base .
Apart from this I have a 2000L pump , pumping water from the pond through my waterfall.
I have a small air pump with 2 airstones connectted , for the other 2 conreners so the water does not remain stagnant .
I have increeased the height sfrom hich my filter is , so the water drop is now about a metre thus creating movement in the water .
Lots of algae has built up to a point were I cannot see the koi , all except the white one.
I had 5 koi , all at around 25 to 30 cm , which still is fine considering the size of the pond

Hi Devan,

I agree with Paul, but I think that if the power is off for 3 hours or less, the “back bacteria” will behave themselves.

If there were still algae in your pond during the “power cuts,” I am sure that the problem was oxygen. Algae use a lot of oxygen during the night.
Normally Goldfish could go a long way without oxygen and this to me points to a gill problem with the two dead fish.

You should check the expiry date of your test kit! The ammonia level could be never zero with the amount of algae and fish.

I suggest that you get someone to have a look at your filter system.
I have used Potassium Permanganate with algae blooms, but with all this “power cuts” it could be fatal without enough oxygen supply.

HI all

The ammonia test this weekend showed a light green color .
I have the one were yo utake 5 ml sample water and use 14 drops of some liquid and 7 drops of 2 other bottles of NH3 ??
Forgive me for my ignorance .
it read as 1,5 parts , and on the diaagnostic sheet , it stated high but not fatal .
I did 2 things this weekend , I checked if the UV light is working , which it is .
And I also skimmed the top as Algae seems to be forming on the top -
I shoudl have checked the 2 dead fish and the gills as I am sure is has someithng to do with the O2 levels as the ones that did are constanley at the waterfall.
Should i cover the pond with a shade cloth as Algae grows wild with sunlight , also with my 10 % water changes, is the new water not ideal breeding grounds for Algae ?Can I get potassium premangante to clear up the algae ?

Hi Devan, herewith a few remarks

* You could consider "pond clear", a chemical that is quite effective, but I would use it only of the situation is critical.
* Potassium will help to clear the pond as it oxidises the algae. Once again, I would only use this option if the situation is critical. Potassium takes away quite a lot of oxygene during treatment and influences your filter, although the long term effect is good. I believe one should stay away from chemicals as far as possible.
* A high salt level(0.3-0.5%) will probably solve your algae problem and works on the stress levels of the fish and combat any parasites due to the stress they went through. It also does not affect your nutrifying bacteria as apposed to Potassium.
* One of the contributing factors for your algae bloom is probably the amount of fresh water during your water changes. It ads a lot of Nutrients to the water and the algae loves it and your water turns green.
* If you have plants, maybe your soil in which they are planted is very rich, in which case you will have an algae bloom. On the one hand, the presence of plants prevents an algae bloom because it competes with the algae, on the other hand the soil(if rich), will stimulate algae growth. If you are going to treat with a high concenatration of salt, you will have to take out the plants if any.
* You say that you have checked that your UV is working. Remember that the fact that the tube goes on, does not necessarily mean that it is working. The tube is only effective for approximately 12 months, although it will still burn.
* Remember that because your stock is now very low, there are less fish to control the algae, and you will have to compensate.
* If you cover the pond with shade cloth, it will combat the algae growth, thereby increasing your oxygen levels, and cool your pond down. Remember, the colder the water, the higher the oxygen levels.

My advice, treat with a high concentration of salt and monitor your Ammonia and Nitrites. Only do more than 10% water changes per week if your Ammonia and Nitrites are at an unacceptable level. Feed only every second day to keep the Ammonia and Nitrites at bay, until your pond is in balance again. Manually remove blanket weed if present and cover with shade cloth until you got rid of the algae.

Hi guys

well adding a shade cloth seems to be doing the trick , the pond was absolutley green and after a few days , I could see the bottom, this mronign i could see the entire lot of fish , so it has improved tenfold.
As much as I am happy that the colour has returned , the koi are still swimming around normally as they were when there was an abundance , so that is a good sign.
I am trying to invest in a Venturi as suggested by your site , any other options except this as some parts of the pon still remain stagnant