Trouble with Plecos

[toddwcpa]

Hi all -

I have a 46 gallon aquarium with some Rainbowfish, an Acara cichlid, Blood Parrot cichlid, and some cory catfish. I really like plecos but each one that I've added died. Can't figure out why. Years ago, I had a common pleco and it grew to over a foot long. The ones I have purchased recently were all quite small. But none of my fish are aggressive. They usually hide in the aquarium for a couple of weeks and then turn up dead. I'm afraid that they could be starving to death. But I have driftwood and offer algae wafers. The tank is cleaned regularly - I do 25% changes about three times a month. And it has a Fluval cannister filter. I will say that I keep the lights on only a few hours a day because using a programmed light I had serious algae blooms.

Unfortunately, I've tried about six different plecos - some pretty expensive. Bristlenose, clown, gold spotted, yellow blue-eyed, calico... they've all died. The only thing I haven't tried this time is a common pleco.

Any suggestions??

 

[Colin_T]

Picture of the entire aquarium?

What are the aquarium dimensions (length x width x height)?

What is the ammonia, nitrite, nitrate and pH of the aquarium water?
How often and how do you clean the filter?

What is the GH (general hardness) and KH (carbonate hardness) of your water supply?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

When you do water changes, do you gravel clean the substrate?
Do you dechlorinate the new water before adding it to the tank?

Do you have driftwood and algae in the tank?

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If you have big cichlids, you might have high nitrate levels, which will kill catfish very quickly. I would do a bigger (50-75%) water change and try to do them each week (say every Saturday). You should gravel clean the substrate every time you do a water change.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Established biologial filters should be cleaned at least once a month. If they contain sponges and other filter media/ materials, squeeze the media out in a bucket of tank water and re-use the media. Tip the bucket of dirty water on the lawn.

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Rainbowfish need plenty of plant matter in their diet and at least 50% of their diet should be plant based. You can grow soft leaf plants in the tank like Duckweed and Ambulia, and feed them vege flakes or marine algae (available from Asia supermarkets or the Asian food section in normal supermarkets). The marine algae can be bought in a dried or frozen form. Frozen is my preferred choice but either is fine.

 

[toddwcpa]

Definitely appreciate the in-depth considerations. The aquarium has thirteen other fish and several live plants, all healthy. I think the problem has to be that the plecos have all been too small. They immediately hide behind the heater or inside a statue in the tank and I never see them again until I find the dead body (usually one to two weeks after purchase). So, I think they are probably starving because they're afraid to come out. The cichlids, while non-aggressive, are 4-5 inches long and must seem like giants to these little plecos which have all been about an inch and a half or smaller. I try feeding them algae wafers, but they never come out to eat. I've just assumed, being so small, that they were getting enough nourishment from the surface wherever they are hiding.

The tank has driftwood and live plants. And I do vacuum the gravel and dechlorinate when adding water. The filter media is always changed according to schedule. I will try using tank water to clean the sponges; have never done that before.

I've thought of just buying a larger common pleco to see how that works since I don't want to drop $100 on a bigger exotic type. But then, if it lives, I'll be stuck with the common pleco when I want something more colorful. Common plecos are cool too but I just wanted something more unusual.

 

[Colin_T]

You don't want to change the filter media because you get rid of the beneficial bacteria that keeps ammonia and nitrite at 0ppm. If you get any reading of ammonia, it can kill fish and catfish are more sensitive to poor water quality than most other fishes.

Most catfish are nocturnal and will hide during the day and come out at night to feed.

 

[ColdKoi]

I don’t think I’d attribute it to the plecos size. In my experience, I added 3 baby bristlenose to my 75 which already had a red tail shark and a dozen tiger barbs all at least triple the plecos size and had no issues at all.

On that same note, size aside, it can still be a territorial issue going on in your tank. If the plecos were being outcompeted for food it would make total sense why you’ve been having bad luck with them. Especially a larger variety and most definitely a common pleco, they are big fish and they require a fair amount of food to stay healthy.

Like mentioned, try to clean the filter media you have instead of replacing it. Much less chance of having a swing in your water quality which can definitely be deadly on a fish that’s already stressed out. Also not mandatory (I don’t always follow this and don’t have issues) but there’s a lot less chance of having issues with your water quality if you stagger your maintenance (water change/gravel vac one week, clean the filter the next week kind of thing). If you go and ‘clean house’ all in one day you can stir up way too much bad stuff as well as remove way too much beneficial bacteria at one time, not good!

 

[toddwcpa]

Thanks. The last one did die the day after I changed water and filter media. Not sure if that was the cause because no other fish had a problem. But your tip makes sense.

Also, I have a little school of four cory catfish who clean up any food that makes its way down to the gravel. Since there are no other plecos, a baby pleco, in theory, should find some algae on the glass and also be able to eat the driftwood. I would drop in pleco wafers but never saw him eat it. In fact, I never saw him leave from his hiding place behind the heater. Previous plecos have hid inside a statue I have in the tank, never to be seen again. I always thought they were some of the easiest fish to keep because they are so tough. That's why this is stumping me.

 

[Jacky12]

Hi, how small are these plecos? Can you isolate them in a smaller tank until they get bigger? I’ve seen used 10, 15, 20, & 29 G setups cheap at local Facebook groups & on Craigslist. Also Petco & other big box stores offer smaller tanks at 50% off on a regular basis. The other required equipment is best priced at Amazon.

 

[toddwcpa]

I've thought about it! But I would have to REALLY want a pleco to start another aquarium just for that purpose.

 

[Jacky12]

Yeah, I hear ya. I want 2 or 3 golden dojo loaches, but am only seeing 2” ones online that have $40 dollar shipping fees. I really don’t feel like setting up a grow tank now and need to find out if my 7” cinnamon brown dojos would pester the little guys.

I see often free plecos offered in the local Facebook group. Last I saw was a foot long ugly sucker IMO. Maybe you could find some cute smaller ones.

 

[toddwcpa]

Quick follow up to this thread to says thanks for the input.

I decided to try one more time and bought a common pleco that is a little larger, maybe 3 inches long. He's doing much better. I think maybe the very small little baby plecos must simply be harder to add to an established aquarium. Too bad I wasted so much money, and lost the lives of several little fish, trying to add more exotic baby plecos.

 

[Jacky12]

I’m sorry for your losses. It’s like they say: live and learn.
I’ve had good results with older fish purchased from private parties, or given away at no cost. I saw some attractive plecos the other day, think they were yellow, in a local FB group. All in all these secondhand fish have been healthy. If you intend to get more fish or bigger tanks etc take a look at these local FB groups or Craigslist.