Any downside to putting a cucumber in the tank?

[Tiber]

I was in the LFS yesterday and my wife noticed they were putting cucumbers into a (very enthusiastic) pleco tank. And now she would very much like to do this with our tank.

In all my years keeping fish I have never considered just tossing a sliced vegetable in the tank. Is this all good or can it cause issues?

I assume you remove it after a few hours so it doesn't rot in the water?

 

[Ichthys]

You can leave it in for a day or two and it won’t cause any issues. Just remove it before it turns to mush (for practical purposes). Use organic, because non-organic cucumbers are laced with pesticides.

 

[AdoraBelle Dearheart]

You can feed all sorts of fruits and vegs to different fish in a tank! As you saw with the pleco tank and cucumber, that's a nice easy one for them to eat, and being long, means a few can get onto it and munch happily away.

Most things, like cucumber, best to par-boil then blanch them first, so they're softer and easier for the fish to eat. Just boil the veg for two minutes or so (timing depends on the veg, I only rinse spinach for example) then drain, and plunge the cucumber into bowl of ice cold water/water with ice in it.

Don't be surprised if it takes a few attempts for the fish to recognise this new item to them as food, if they haven't been fed fresh food before. You can get veggie tank clips for this purpose, to hold the food where you want it, or you can weight something down by sticking a fork in it to weigh it down and keep it from floating.

Check out some pleco feeding youtube channels, or do a search on the forum, for the kinds of things you can try! Lots of other fish and inverts like shrimp and snails appreciate a treat like this now and then too.

Yes, uneaten food of any kind can rot and produce ammonia if left in the tank too long. I tend to feed items like that just before bedtime/tank lights going out, then remove the rest by the morning. But how quickly it'll be a risk for ammonia depends on how fast that particular food item breaks down, depends on what it is, how heavily stocked the tank is, if there are a lot of live plants to help with sucking up ammonia etc. Just be sensible and don't leave it to rot in the tank. I tend not to leave anything for longer than about 12 hours, and haven't had a problem.

 

[Ichthys]

Most things, like cucumber, best to par-boil then blanch them first, so they're softer and easier for the fish to eat.

I strongly disagree. Veg soften in water, and release different compounds at different stages of their breakdown. This means they taste different at different stages. Some fish prefer them when they’re still hard, others wait till they’ve softened. Most of the plecs I’ve kept prefer them hard. I never blanch anything. Put it in unblanched and let the fish decide when to eat it.

 

[GaryE]

This summer, I will grow and freeze zucchini. I know the UK has another name for it, but I can't recall it.
I cut it into coins, with wax paper between each coin and freeze it solid. The freezing softens it once it thaws again, and all herbivores, especially Loracarids, love it. There isn't a lot of nutrition in cucumbers, or I could grow them too.
I don't disagree with @Ichthys, but I also like removing the empty rind at the end of the day.

 

[Ichthys]

Courgette.

 

[AdoraBelle Dearheart]

I strongly disagree. In water, veg release different compounds at different stages of their breakdown. This means they taste different at different stages. Some fish prefer them when they’re still hard, others wait till they’ve softened. Most of the plecs I’ve kept prefer them hard. I never blanch anything. Put it in unblanched and let the fish decide when to eat it.

This summer, I will grow and freeze zucchini. I know the UK has another name for it, but I can't recall it.

In my defence, I did say that it depends on the food! Like how I don't wilt spinach before feeding or anything Plus getting their plecs used to taking fresh fruit and veg, sometimes the softening first helps them realise it smells and tastes good.

I also started with, and feed a good amount of courgette (zucchini to you weird US/CA folks! ) because it's one I often have in the fridge anyway, and mine wouldn't touch it until it was part-boiled and blanched. But my plecs might be fussy, who knows!

 

[AdoraBelle Dearheart]

I never blanch anything. Put it in unblanched and let the fish decide when to eat it.

How long would you say it's okay to leave it in the tank for? I've always erred on the side of caution, being more of a newb to this, but if you leave it longer without issue, that would be reassuring!

 

[Ichthys]

How long would you say it's okay to leave it in the tank for?

With cucumber, I only remove it because if you leave it in too long it breaks apart and you get little bits of mush floating around everywhere. If fish are still eating it I leave it until just before this happens (couple of days. It’s pretty soft by the second day). Otherwise it comes out when the fish aren’t interested any more.

If your fish don’t eat it till it’s softened, then you may as well blanch it.

I’ve found that Pterygoplichthys (and dollars) eat the seeds first (I give them a quarter... a half sliced lengthways). BNs like the skin...

 

[AdoraBelle Dearheart]

With cucumber, I only remove it because if you leave it in too long it breaks apart and you get little bits of mush floating around everywhere. If fish are still eating it I leave it until just before this happens (couple of days. It’s pretty soft by the second day). Otherwise it comes out when the fish aren’t interested any more.

Oh, cool! If it can stay in a couple of days, then I can relax my "get it out first thing in the am" rule.

If your fish don’t eat it till it’s softened, then you may as well blanch it.

Might also depend on what other fish you have in the tank, and how many. I also boil/soften veg for my oto/pygmy cory tank, and it seems to work better for the otos, maybe because they don't have such strong raspers as plecs do? In the bigger tank I only have the two fairly small plecos (L181's), and otherwise it's the livebearers and occasionally cories pecking away at it. Oh, and the shrimp cover it of course, but it's never eaten down to the rind with so few fish that go for it.

I’ve found that Pterygoplichthys (and dollars) eat the seeds first (I give them a quarter... a half sliced lengthways). BNs like the skin...

I had to look up the latin name, lol! Are you feeding tanks with a fair number of plecos then? Plus the large sailfins?

 

[Ichthys]

I’ve had a few Common Plecs (Pterygoplichthys spp), mostly one at a time. I love the Gold Spot, which ‘only’ gets to a foot long, standard length. I’ve had a few of the bigger species but only as rescues.

Big raspers, yes, they can eat unblanched carrots... and here I think I need to add a disclaimer. I’ve generally kept big fish, which means my filters have bacterial colonies hundreds or thousands of times as big as a filter for tiddlers. So a piece of veg left in too long isn’t a problem. In a tank of small fish it might be.

 

[TwoTankAmin]

I do not use cuke as it's nutritional value compared to other veggies is low. I do the pre-cut and freeze using wax paper. When I want to feed I nuke slices on defrost and then drop them into cold water. If it sinks not long after, it is ready to feed, If not I give it another round in the micro. I prefer self sinking to having to attach or spear it. That said, I have veggies clips I can use. One or the more amusing things I have seen is when there was nothing left but a ring of skin I watchec one of mu Montezuma swords swim though that smaal green hoop.

But, Repashy also has a few good option in this respect. I use Soilent Green for one. But there is another neat food in this vein called Igapo Explorer (it was originally called Fruit Luups). The ingredients were determined by Dr. Staphan Tanner of Swiss Tropicals. Here is the ingredient list:

"Our formula for all Rainforest Species. Contains Invertebrates, Nuts, Fruits, Seeds, Legumes, Herbs and Greens."

INGREDIENTS: Black Soldier Fly Larvae Meal, Krill Meal, Banana Powder, Squid Meal, Mango Powder, Pea Flour, Mulberry Fruit Powder, Dandelion Powder, Seaweed Flour, Almond Flour, Coconut Flour, Ground Flax Seed, Alfalfa Meal, Locust Bean Gum, Citric Acid, Lecithin, Stinging Nettle, Garlic, Ginger, Cinnamon, Phaffia Yeast, Dried Watermelon, Rosehips, Hibiscus Flower, Marigold Flower, Calendula Flower, Paprika, Turmeric, Dried Kelp, Calcium Propionate and Potassium Sorbate (as preservatives), Magnesium Amino Acid Chelate, Zinc Methionine Hydroxy Analogue Chelate, Manganese Methionine Hydroxy Analogue Chelate, Copper Methionine Hydroxy Analogue Chelate. Vitamins: (Vitamin A Supplement, Vitamin D3 Supplement, Calcium L-Ascorbyl-2-Monophosphate, Vitamin E Supplement, Niacin, Beta Carotene, d-Calcium Pantothenate, Riboflavin, Pyridoxine Hydrochloride, Thiamine Mononitrate, Folic Acid, Biotin, Vitamin B12 Supplement, Menadione Sodium Bisulfite Complex).

GUARANTEED ANALYSIS: Crude Protein min. 30%, Crude Fat min. 8%, Crude Fiber max. 5%, Moisture max. 8%, Ash max. 10%.

My Clown Loaches shred this stuff before it even nears the bottom of the tank. My plecos like it as well.

 

[Tiber]

Thanks for the advice foks. I gave it a try tonight (also took the advice about using cutlery to weigh it down!)

The two plecos I bought it for are utterly ignoring it (one is lurking in the background of the attached picture) but my live bearers and female fighters are fascinated

 

[sharkweek178]

This is sort of the equivalent of feeding live foods to predatory or omnivorous fish. I don't think any animal should have a diet of only processed foods so I encourage it.

 

[sharkweek178]

Thanks for the advice foks. I gave it a try tonight (also took the advice about using cutlery to weigh it down!)

The two plecos I bought it for are utterly ignoring it (one is lurking in the background of the attached picture) but my live bearers and female fighters are fascinated


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You might want to slice it in half and scoop out the seeds. Fish don't really eat the skin. You want them to have more access to the fleshy part.