How much should I feed my fish?
December 7, 2022 3:39 PM Subscribe
I'm a novice fishkeeper. I inherited six common feeder goldfish in April. For REASONS (which I'm sure you can guess), these six five 29-cent goldfish now live in a well-filtered 70-gallon tank with a pleco, four molly (plus fry), and five four cory. Here's my question: How can I tell when my fish are actually hungry?
I ask because the frickin' goldfish seem like they're hungry all of the time. All of the time. They're looking at me now, their sad eyes pleading for more food. I feed the tank twice (rarely three times) per day — just as much as the fish can eat in two or three minutes. The goldfish are very vocal that this is Not Enough. Are they right?
I should note that two of the five goldfish have ballooned in size since I got them eight months ago. They've gone from maybe two inches long to roughly four and five inches long. The biggest guy (Walt) has a bad habit of eating the molly fry. He also ate (and nearly choked to death on) one of the cory, which is why there are five cory now and not four.
I'm feeding them a variety of foods. I have four types of flakes, some "goldfish crumbles", and some "vibra bites". The goldfish like all of these things. The other fish are more selective. Oh, and I throw one algae pellet in the tank per day for the pleco. The goldfish want it too, but the pleco fights them off until he's finished with his share. Lastly, there are plenty of plants in the tank, and the biggest goldfish do indeed snack on these (pulling them out of the gravel in the process).
I ask because the frickin' goldfish seem like they're hungry all of the time. All of the time. They're looking at me now, their sad eyes pleading for more food. I feed the tank twice (rarely three times) per day — just as much as the fish can eat in two or three minutes. The goldfish are very vocal that this is Not Enough. Are they right?
I should note that two of the five goldfish have ballooned in size since I got them eight months ago. They've gone from maybe two inches long to roughly four and five inches long. The biggest guy (Walt) has a bad habit of eating the molly fry. He also ate (and nearly choked to death on) one of the cory, which is why there are five cory now and not four.
I'm feeding them a variety of foods. I have four types of flakes, some "goldfish crumbles", and some "vibra bites". The goldfish like all of these things. The other fish are more selective. Oh, and I throw one algae pellet in the tank per day for the pleco. The goldfish want it too, but the pleco fights them off until he's finished with his share. Lastly, there are plenty of plants in the tank, and the biggest goldfish do indeed snack on these (pulling them out of the gravel in the process).
You could try letting them eat for an extra minute or two at each feeding?
posted by nouvelle-personne at 4:30 PM on December 7, 2022
posted by nouvelle-personne at 4:30 PM on December 7, 2022
Sorry for not really answering the question straight away, but goldfish do not belong with tropical fish. They produce epic amounts of waste, which leads to terrible water conditions for the more sensitive tropicals. Goldfish are pond fish, and they best thing you can do is give them away to someone with a pond. They're already at the limit of your ability to house them. As you found out, goldfish will eventually try to eat any fish small enough to fit their mouths; a Corydoras has sharp spines in its fins that will wedge it in the goldfish's mouth, usually killing both. Yours was lucky. I've heard of a lot of cases of fatalities this way.
To answer the question, Corys need a specialist sinking food, high in insect, worm or similar protein. They will not get any benefit from algae pellets. You can buy specialist sinking catfish pellets online. They also benefit from live foods such as daphnia, bloodworm and blackworm. Plecos like algae pellets, but also benefit from vegetables (you can look up how to use these as foods). Mollies are another tropical species, preferring a slightly higher temperature than Corydoras. They are also often a bit too aggressive to keep with Corys. They'll do fine on flake.
Generally, feed whatever the fish will consume in a reasonable time. Watch the fish. Reduce feeding at the first sign that they're leaving excess food. Reduce or increase feeding depending on how the fish look. Once a day is fine for most fish, and if you have to leave them for a few days, it's fine. Another issue with goldfish is that they'll often get all the food by dint of size and temperament, so you'd need to make sure the other fish are actually getting food. And you'll need to keep a really close watch on ammonia, nitrite, and nitrate levels (get liquid test kits). Goldfish will foul the water quickly, as will overfeeding; unless your biofiltration can handle it, you'll get an ammonia/nitrite spike and the fish will quickly become sick and die. Seriously, get rid of the goldfish.
posted by pipeski at 4:34 PM on December 7, 2022 [14 favorites]
To answer the question, Corys need a specialist sinking food, high in insect, worm or similar protein. They will not get any benefit from algae pellets. You can buy specialist sinking catfish pellets online. They also benefit from live foods such as daphnia, bloodworm and blackworm. Plecos like algae pellets, but also benefit from vegetables (you can look up how to use these as foods). Mollies are another tropical species, preferring a slightly higher temperature than Corydoras. They are also often a bit too aggressive to keep with Corys. They'll do fine on flake.
Generally, feed whatever the fish will consume in a reasonable time. Watch the fish. Reduce feeding at the first sign that they're leaving excess food. Reduce or increase feeding depending on how the fish look. Once a day is fine for most fish, and if you have to leave them for a few days, it's fine. Another issue with goldfish is that they'll often get all the food by dint of size and temperament, so you'd need to make sure the other fish are actually getting food. And you'll need to keep a really close watch on ammonia, nitrite, and nitrate levels (get liquid test kits). Goldfish will foul the water quickly, as will overfeeding; unless your biofiltration can handle it, you'll get an ammonia/nitrite spike and the fish will quickly become sick and die. Seriously, get rid of the goldfish.
posted by pipeski at 4:34 PM on December 7, 2022 [14 favorites]
2x daily feedings is a lot. I'd recommend every other day, and feeding only what your fish can consume in about 2 minutes. Make sure everyone in the tank is getting some food.
Fish will instinctively gobble up food, it doesn't mean that they're actually hungry or in need of the nutrients. Overfeeding can lead to bloat and constipation.
posted by Drosera at 5:40 PM on December 7, 2022 [3 favorites]
Fish will instinctively gobble up food, it doesn't mean that they're actually hungry or in need of the nutrients. Overfeeding can lead to bloat and constipation.
posted by Drosera at 5:40 PM on December 7, 2022 [3 favorites]
Also one algae wafer per day for 1 pleco and 4 corys is way too much. You risk generating a lot of wasted food, which rots and adds to the ammonia production in your tank.
posted by Drosera at 5:43 PM on December 7, 2022 [1 favorite]
posted by Drosera at 5:43 PM on December 7, 2022 [1 favorite]
Response by poster: Thanks, all. I will ignore the ever-hungry goldfish. And I will consider rehoming the largest.
posted by jdroth at 8:09 PM on December 7, 2022 [1 favorite]
posted by jdroth at 8:09 PM on December 7, 2022 [1 favorite]
The thing about gold fish is that goldfish are carp, and people have been breeding them for many many centuries in fish ponds or in large tubs so that they could eat them. This means the species can survive in foetid stagnant puddles, can even survive in brackish water, will eat any old crap and are driven to grow as rapidly as possible to a size where the other goldfish can't eat them, and they can eat all the other fish. They take the least possible time to go from being teensy new born fry to becoming a nice size to feed a family of twelve a nice dinner of fish and rice.
In Europe during medieval times if you didn't live within a convenient distance from the sea to get fresh fish you were kind of screwed during fast days unless you had a fish pond. And fast days were Wednesday and Friday of each week, plus 40 days of Lent, Rogation Days, Ember Days, Advent and whenever you thought you had sinned so much that going off flesh and fat would benefit your soul. Or when your local priest said so because the king was reported to have a fever.
Every instinct that a gold fish has is to eat until it becomes a behemoth. And in fact they don't stop growing if they can get the food. Here is a picture of a twenty year old goldfish that weighs 67 pounds.
Goldfish then, are like bonsai trees. If you want them to be tiny stunted little things of a size to live in a small pot, you have to deprive them of nourishment and the room to grow. If you provide them with the nourishment they want they will promptly outgrow the pot and pollute it enough that only surface breathers like themselves can survive. If you take generous care of them you won't have a bonsai tree, you'll have a 35 foot tall oak.
Goldfish are not tropical fish. Many species of them can survive the winter by hibernating at the bottom of their pond under the ice. They really need a goldfish bowl of their own, rather than being in with your tropical fish. Instead of a heater and the aeration system that filters the water, they will do just fine being scooped up and transferred into a bowl fresh water once a week or so. They require completely different things than tropical fish do. They even have gills that handle being in a net and transferred through the air without damage or danger to the fish.
This book once very well known, describes what happens if you over feed a gold fish. It's really easy to do, and so very, very tempting... but the consequences are definitely something to avoid.
posted by Jane the Brown at 8:13 PM on December 7, 2022 [4 favorites]
In Europe during medieval times if you didn't live within a convenient distance from the sea to get fresh fish you were kind of screwed during fast days unless you had a fish pond. And fast days were Wednesday and Friday of each week, plus 40 days of Lent, Rogation Days, Ember Days, Advent and whenever you thought you had sinned so much that going off flesh and fat would benefit your soul. Or when your local priest said so because the king was reported to have a fever.
Every instinct that a gold fish has is to eat until it becomes a behemoth. And in fact they don't stop growing if they can get the food. Here is a picture of a twenty year old goldfish that weighs 67 pounds.
Goldfish then, are like bonsai trees. If you want them to be tiny stunted little things of a size to live in a small pot, you have to deprive them of nourishment and the room to grow. If you provide them with the nourishment they want they will promptly outgrow the pot and pollute it enough that only surface breathers like themselves can survive. If you take generous care of them you won't have a bonsai tree, you'll have a 35 foot tall oak.
Goldfish are not tropical fish. Many species of them can survive the winter by hibernating at the bottom of their pond under the ice. They really need a goldfish bowl of their own, rather than being in with your tropical fish. Instead of a heater and the aeration system that filters the water, they will do just fine being scooped up and transferred into a bowl fresh water once a week or so. They require completely different things than tropical fish do. They even have gills that handle being in a net and transferred through the air without damage or danger to the fish.
This book once very well known, describes what happens if you over feed a gold fish. It's really easy to do, and so very, very tempting... but the consequences are definitely something to avoid.
posted by Jane the Brown at 8:13 PM on December 7, 2022 [4 favorites]
By the way, you are a good fish parent.
Check with a reputable local supplier about rehoming the larger fish. Be advised that a backyard koi pond is also a magnet for raccoon, feral cats, and other predators.
If you go that route, carp swimming among the waterlilies is a delightful site. Keep in a shaded area (sunlight will heat up the shallow pool to intolerable levels) and remove leaves and other debris from time to time.
The neighbor with the koi pond removes her fish in the coldest weather and covers the pond with a net until spring.
posted by TrishaU at 9:48 PM on December 7, 2022 [3 favorites]
Check with a reputable local supplier about rehoming the larger fish. Be advised that a backyard koi pond is also a magnet for raccoon, feral cats, and other predators.
If you go that route, carp swimming among the waterlilies is a delightful site. Keep in a shaded area (sunlight will heat up the shallow pool to intolerable levels) and remove leaves and other debris from time to time.
The neighbor with the koi pond removes her fish in the coldest weather and covers the pond with a net until spring.
posted by TrishaU at 9:48 PM on December 7, 2022 [3 favorites]
Sorry about losing the molly fry, but honestly, mollies are libidinous and will readily make more, plus mollies will eat their own fry given the opportunity, so honestly no big there.
You can give yourself permission to not keep the goldfish. They are incredibly cheap for a reason - they're meant to feed other animals. It's in the name.
I would definitely not keep the goldfish with the tropicals. I had a friend growing up who won some feeder goldfish at a school fair in 1st grade and still had them 11 years later when he graduated. His family kept them in a small pond during the warmer months with chicken wire to dissuade the raccoons and brought them in to their own tank in the cold months.
To address the actual question: fish don't need a lot of food. Yeah, every other day is fine.
posted by plinth at 8:49 AM on December 8, 2022 [1 favorite]
You can give yourself permission to not keep the goldfish. They are incredibly cheap for a reason - they're meant to feed other animals. It's in the name.
I would definitely not keep the goldfish with the tropicals. I had a friend growing up who won some feeder goldfish at a school fair in 1st grade and still had them 11 years later when he graduated. His family kept them in a small pond during the warmer months with chicken wire to dissuade the raccoons and brought them in to their own tank in the cold months.
To address the actual question: fish don't need a lot of food. Yeah, every other day is fine.
posted by plinth at 8:49 AM on December 8, 2022 [1 favorite]
If there's any way you can have a pond, they're fun and don't have to be fancy! Some years ago in western NC I found a bathtub on the side of the road, dragged it home and paid my son and his friend $20 to dig a bathtub sized hole in the ground. We filled it with water, dropped some 25 cent feeder goldfish in it and basically forgot about it. Those goldfish lived for years and got huge. The bathtub froze every winter and thawed every spring and that didn't faze the goldfish at all. They lived on mosquito larvae and were happy. What I'm saying here is even if you live in a studio apartment in a high rise, a big rubbermaid container on a balcony will keep your goldfish just fine. Drop some plants in there. Let nature do the rest.
posted by mygothlaundry at 1:13 PM on December 9, 2022
posted by mygothlaundry at 1:13 PM on December 9, 2022
This thread is closed to new comments.
posted by jdroth at 3:42 PM on December 7, 2022