How big are these granules? Do the fish look thin? Obviously what and how much you feed pond fish varies with season and temperature but that sounds very little over the summer uless the pond is teeming with insect etc life
Hi - these are probably 3-4 mm size. Well, they dont look fat! Not obviously thin though (though no guarantee i would know what a thin goldfish looks like from a distance). Some insect life of course and a couple of frogs (which are always around in the garden). Maybe more plants and more food then?
Hi, Just a quick comment on the filter. I have an Oase Filtoclear and I am assuming your Oase is something similar? For the Filtoclear, it does recommend regular cleaning (the manual says regular, a shop-added advice sheet specifically for that filter said weekly). Sorry if that contradicts what you said Jellybean. I clean mine every week and plenty of green sludge comes out every time. With these types of filters, they are very simple to clean and they automatically use the pond water to flush the filters.
As others have said, water quality is a likely suspect. A decent testing kit or the services of a LFS will help there.
If the fish are dying during hot weather then aeration may be the issue. Lots of agitation on the surface from e.g. a fountain, waterfall, airpump is a good thing. If you have too many oxygenating plants then they could cause problems during the hottest nights as they take oxygen OUT of the water during the night.
As Iain_clark has also said, check for any chemicals that might be getting into the pond. e.g. Any water that runs into your pond may contain chemicals from any treatments that have been applied to the lawn/garden. Paints/Sprays for fences can be deadly to fish too.
Hi - many thanks for the further input. A potential solution is not getting any clearer though. I did say i tested the water quality regularly and posted the data on the site (all of which confirm, i think, that the water is fine). No chemical spraying in the garden at all. I do clean the Oase Filtoclear once a week - never green sludge just deep brown muddy water flushes out. When you say clean out you mean using the "sponge squashing manual pulley thing" rather than actually taking the unit apart?? Not dying during hot weather - all through the year.
Yes I do mean pulling the handle up and down a dozen times then flushing it out via the non-pond outlet (cant remember what it is officially called). My filter is 2 years old and I havent touched the insides of the filter at all except to replace the UV bulb.
Sorry, I didn't see any actual readings for water quality. I've just noticed where you mention them, and yes I would recommend you test for nitrite too. My normal Ammonia/nitrite/nitrate readings are 0/0/0 using a kit similar to API Master freshwater Test Kit.
Hi - thanks for your time again. So, my use of the pump sounds all fine. I will get a nitrite test kit but would would never get 0,0,0 for ammonia, nitrite and nitrate (ever probably for tap water!). I am a Professor of Chemistry also so have a vague idea! Would you mind me asking what you do if your nitrite/nitrate/ammonia or pH levels are not spot on? Presumably just pump out some water using the Oase then add fresh water (with de-chlorinator if appropriate)? JJD
At the same time as cleaning the filter, I pump out anywhere up to 25% of the pond water (my pond is ~800 liters), normally maybe 10%. This is normally every week.
To fill the pond back up I add some Tetrapond Watersafe Pond Water Treatment and then top up with tap water via a hose.
I can't remember getting anything but 0 or next to 0 ammonia and nitrite, especially since the pond was first set up. The nitrates have never got too high. I have always assumed the regular water replacement, and the high number of plants in the pond have always helped.
Hi, thats very helpful thanks. I certainly do not pump out and replace water that frequently - maybe once a month or when i notice the level has dropped through evaporation. Can you recommend any particular plant types (apologies for my ignorance)? Do you think an additional air pump a waste of time (we do have a sizeable waterfall dropping water back into the pond)? JJD
I am by no means an expert, so please don't take all this as hard fact!!
The air pump is all about aeration. Its not so much about bubbles in water, but all about agitating the surface of your pond. If your waterfall creates a lot of surface movement over the pond then you might be ok (I don't know how much is enough).
I added a cheap fountain last year to help aeration, and this year I have replaced it with a proper air pump. Its hard to tell if it has helped, but it certainly hasnt harmed the pond and the fish didn't seem at all phased with the hot weather this year. I am not sure whether I need to run it all year round though, once the fish start to slow down and the plants stop growing then I might turn it off.
The plants I have are: Elodia Crispa (it grows fast, an oxygenating plant) Water soldiers (the fish love swimming under them) 2 water lillies (the fish love the pads) And a tall plant that I cant remember its name (it flowers nicely, no idea if its good for the pond) Oh, and lots and lots of string algea. I have to take out handfulls of the stuff every week, its crazy stuff.
One thing about my pond is that it doesnt get a lot of direct sunlight, maybe 2 hours a day. Plenty of light otherwise, just not direct sunlight.
rubadub wrote: Hi, Just a quick comment on the filter. I have an Oase Filtoclear and I am assuming your Oase is something similar? For the Filtoclear, it does recommend regular cleaning (the manual says regular, a shop-added advice sheet specifically for that filter said weekly). Sorry if that contradicts what you said Jellybean.
No problem, its best to iron these things out to get it right. I only have a tank to refer to which doesn?t need the filter cleaning quite so often so i thought this could have been an issue.
Ammonia and NitrIte should be at 0 in a healthy tank/pond, this is taken care of by the filter which holds majority of nitrifying bacteria, nitrate being the last stage is kept under control (in a tank) by regular water changes.