Goldfish Proof Plants?

[aquila]

Any ideas for goldfish-proof plants for a coolwater (20 degrees c) 180l established tank with stock lighting, no c02, regular doses of flourish excel? So far I've been relying on trial and error which is proving rather costly, as these are the results so far:

Elodea/Egeria Densa - left well alone
Cabomba - left alone at first, now gradually being eaten down to stalks
Giant Vallis - ruthlessly munched, new runners left alone until they reach a certain size, then munched
Cladophora aegagropila (moss balls) - left alone at first, now vigorously eaten
'Creeping Jenny Yellow' - left alone but too slow growing to fill up the gaps
Crinium Thanium - left alone but too slow growing
Java moss and fern - left alone but obviously too small to fill up the background
Some kind of crypt (recommended as being hardy and tolerant of low temperatures) - left alone for now, growing well, but is only a foreground plant

I'm just looking for something other than the elodea to fill up the back of the tank, really

Edited to say: The goldfish are fed several times a day with a huge variety of foods including lots of green things, so there is no excuse for the buggers to be munching on the plants!

 

[DevUK]

Elodea/Egeria Densa - left well alone
Cabomba - left alone at first, now gradually being eaten down to stalks
Giant Vallis - ruthlessly munched, new runners left alone until they reach a certain size, then munched
Cladophora aegagropila (moss balls) - left alone at first, now vigorously eaten
'Creeping Jenny Yellow' - left alone but too slow growing to fill up the gaps
Crinium Thanium - left alone but too slow growing
Java moss and fern - left alone but obviously too small to fill up the background
Some kind of crypt (recommended as being hardy and tolerant of low temperatures) - left alone for now, growing well, but is only a foreground plant

My single goldfish will decimate egeria densa. Gave up on that one long ago. You could look into Crinum's. There are several shapes but they all are long and flowing, but strong leaves that goldfish generally can't munch. I see you've tried Thanium though.

Bog standard java fern should grow quite large given time, but with your setup it will take some time. I had some clumped together in my tropical tank which grew quicker, and then after a re-scape of the tropical tank I put it into the goldfish tank.

My goldfish munched java fern till not much was left, and it would get into the filter inlet and clog it up, so I don't bother with that anymore.

Anubias sp. are strong plants, and quite nice. Again, slow growers in lower light/cool tanks.

I think anything with small bite sized leaves is a no, and anything fragile is also a no. Broad flat leaves usually survive, but you'll have problems finding sub-tropical plants like that really

You'll find goldfish will just eat and eat. They put something in one end and something else pops out the other, hence the reputation for being poop machines, and why they need a lot of water per fish, compared to most other fish.

Good luck

 

[Colin_T]

try feeding the fish nothing but vegetables for a week or so and see if that helps. Feed them as much as they can eat then stop feeding.
You can try various hygrophilla sp but most plants get chomped by vegetarian fish.