Time to get rid of Common Pleco?

[Ikentina]

Hi Folks,
I am having trouble keeping my pH and Ammonia balanced and I’m wondering about the cause. I have a 20 Long with a 2.5” Blue Gourami, 2” Dwarf Gourami (who I believe has had a swim bladder issue for 10 days now), five 1” neon tetras, three 1” Glowlight tetras, two 1” Harlequin Rasboras, a small 1.5” Rainbow shark (just added) one 1” Serpae tetra and what I believe is a contributing factor...a formerly 2” but now 6” Common Pleco. In General, I do believe I’ve been over-feeding and now have reduced from 3 small (1 pinch of Tetra-min flakes) meals/day to 2 (May need to go to 1 meal daily). All of the food is gone from the surface within 45 seconds. However the tetras stay near the bottom and wait for food to fall down but generally they wont eat off the bottom. Seems there is a fair amount of rotting food remnants at the bottom which is why I cut back from 3 to 2 feedings/day. The pH is usu. between 6.0 and 6.4; Ammonia is often between 0.25 - 2.0 ppm (when it hit 2.0 this week I did 2 separate 33% bottom vac/water changes this week) went to 0.25 ppm. I routinely do 1 33% vac/ water change each week. I’m thinking about bringing the Pleco to my local pet shop. Perhaps I‘ll buy 2-3 Cory Cats to replace him? My understanding is that Plecos supposedly make a large impact on the waste in the tank. However I’m not sure that he’s eating much of the fish meal ( Tetra min) at the bottom...first I feed during the day and he’s nocturnal...second Pleco’s prefer Algae to fish meal. Cory’s are diurnal and are less picky eaters so might be a better choice though since they are schooling fish I prob should get 3 of them. Will replacing the Pleco with Cory’s (or other bottom feeder) help or will going from 2 daily feedings to 1 have more of an impact? Thanks in advance for your comments. Note: in Photo Pleco at bottom near filter intake...Dwarf Gourami lying at bottom.

 

[Brp933]

Hi Folks,
I am having trouble keeping my pH and Ammonia balanced and I’m wondering about the cause. I have a 20 Long with a 2.5” Blue Gourami, 2” Dwarf Gourami (who I believe has had a swim bladder issue for 10 days now), five 1” neon tetras, three 1” Glowlight tetras, two 1” Harlequin Rasboras, a small 1.5” Rainbow shark (just added) one 1” Serpae tetra and what I believe is a contributing factor...a formerly 2” but now 6” Common Pleco. In General, I do believe I’ve been over-feeding and now have reduced from 3 small (1 pinch of Tetra-min flakes) meals/day to 2 (May need to go to 1 meal daily). All of the food is gone from the surface within 45 seconds. However the tetras stay near the bottom and wait for food to fall down but generally they wont eat off the bottom. Seems there is a fair amount of rotting food remnants at the bottom which is why I cut back from 3 to 2 feedings/day. The pH is usu. between 6.0 and 6.4; Ammonia is often between 0.25 - 2.0 ppm (when it hit 2.0 this week I did 2 separate 33% bottom vac/water changes this week) went to 0.25 ppm. I routinely do 1 33% vac/ water change each week. I’m thinking about bringing the Pleco to my local pet shop. Perhaps I‘ll buy 2-3 Cory Cats to replace him? My understanding is that Plecos supposedly make a large impact on the waste in the tank. However I’m not sure that he’s eating much of the fish meal ( Tetra min) at the bottom...first I feed during the day and he’s nocturnal...second Pleco’s prefer Algae to fish meal. Cory’s are diurnal and are less picky eaters so might be a better choice though since they are schooling fish I prob should get 3 of them. Will replacing the Pleco with Cory’s (or other bottom feeder) help or will going from 2 daily feedings to 1 have more of an impact? Thanks in advance for your comments. Note: in Photo Pleco at bottom near filter intake...Dwarf Gourami lying at bottom.

I'm not sure a 20g is even big enough for a common pleco as they get to be 12-24". I would try the corydoras

 

[FishGirl115]

Welcome to fishlore! Your tank is most likely going through the nitrogen cycle. Do you know about this? I also spy several problems with your stocking Rainbow sharks need at least 55 gallon tanks and get very aggressive, the blue gourami needs a very large tank as well, and the pleco will grow up to two feet, and all the tetras and rasboras need groups of at least six. I would recommend rehoming the pleco, blue gourami, rainbow shark, and choose one or two type of schooling of fish to keep and get your numbers up to six.
Is the dwarf gourami dead? Doesn't look very alive in the photo

 

[aquachris]

Yeah its time to rehome your pleco. I think Corydoras would be awesome for you though. Some people might bawk at that idea though due to the gravel (some people believe they can harm their barbels) but I've heard of a lot of people not having issues with that.

Oh yeah as FishGirl115 said with the rainbow sharks, those will eventually be an issue.

Your doing a fish-in cycle basically by cycling with fish in it. This is hard on the fish, so it will require a lot more work on your part for water changes unfortunately. However, it is achievable but your going to need to work for it... Definitely get to understand that nitrogen cycle. super important.

 

[jake37]

A 20 long isn't the best tank for cory - i mean you go put in 8 or 9 pygmy but i'd avoid the larger cory. Also if you are getting ammonia something is pretty seriously wrong. You didn't say how long the tank is setup but an over populated tank usually results in high nitrate not ammonia. Ammonia levels of 2 can cause perm. damage to a fish gills so i'd fix that issue before thinking of adding more fishes. As others have suggested I'd also get rid of that common pleco and shark.
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As for the ammonia a couple of additional data points might help - what filter you are using - how do you care for the filter and how long as the tank been setup ?

 

[AquaBaby]

Hi, Ikentina. Welcome to Fishlore!

As mentioned above, you've got quite a lot going on in the tank. The common pleco and rainbow shark both need larger tanks. With the current inhabitants, the pleco, in my opinion, should be rehomed as soon as you can. I'm assuming the rainbow shark is still very small since you just got it. But, it won't stay that small long and they do tend to be a more aggressive fish.

Is there any one of the fishes you have that you are finding you like more than all the others?

You mention you are having trouble keeping your ph balanced. What do you mean by that? Are you seeing big swings? Are you adding something to try to raise/lower the ph?

As far as the ammonia... how long have you had the tank running? You say the pleco started at 2" and is now 6" so I know you didn't set it up last week. Other than the rainbow shark, have you added any other fish recently? You have a pretty big bioload going. Reducing the feeding and vacuuming will help, as will rehoming the pleco.

My guess is, if the tank was previously cycled, you've overwhelmed your cycle by adding too many new fish too soon and/or you've stocked too much and the cycle can't keep up.

I previously asked if there was one of the fish types you have that you're preferring, as you might consider going with one particular kind. Depending on what you choose to keep, if you want input on help with the stocking, there are people here that are great with help on stocking a tank.

Regardless of what stocking you decide to go with, lots of water changes (of course with a dechlorinator if your source water has chlorine), reduced feeding, and rehoming the pleco will help right now.

Also, out of curiosity, what is the ph and ammonia of your source water? And what type of filter(s) are you running on the tank?

 

[Noroomforshoe]

You need to rehome/return the rainbow shark, the pleco and the blue gourami. You need to pick 1 MAYBEY 2 of the schooling fish and rehome/return the rest. Then build up the schools to a minimum of 6 each. But do not get more fish until your tank is cycled and staying cycled, with zero ammonia, zero, nitrite, and nitrate is no longer zero, 10-30ppm.

You should not add fish to clean your tank, any fish you add needs its own food, any fish that eats food, leftover or otherwise, only poos that food out and makes more mess. YOU are the only thing that can remove waste and wasted food. Get your gravel vacuum out every time, still having trouble? consider an eheim quick vac pro for in between water changes.

Also, cories are very social and need to be in a school of 6 or more. 3 is not a school, 6 is a bare minimum school. and ideally, you want bigger or better than the minimum for most things in this hobby. Pygmy cories, maybe dwarf cories in a 20 gallon but not larger species.

Also, Fish meal is a cheap filler. It isn't bad for fish but its low quality left over scraps. The first 5 ingredients of your fish food should include whole fish names, or things like kelp spirulina, insect larva...

 

[RayClem]

The time to get rid of a common pleco is before you ever buy it. Pet stores sell common plecos to unsuspecting fishkeepers all the time. I had one stocked in my 90 gallon tank and it was just fine in that size tank. However, I no longer have the 90 gallon tank. I now have a pleco that is over 10 years old and about 15" long that I keep as the only fish in a 29 gallon tank.

There is absolutely no way that a common pleco can safely be kept with other fish in a 20 gallon tank. Plecos are huge waste factories. To control the waste from my common pleco, I have a HOB filter rated at 400 gpm, a sponge filter rated for a 60 gallon tank, and a 300 gph powerhead fitted with a filter sock..

Common plecos need a tank of 75 gallons minimum and even larger is preferred. The only way I get buy with a 29 gallon tank is that nothing else is in the tank. Get rid of your common pleco. About the only thing suitable for a 20 gallon tank is a bristlenose pleco and some fishkeepers even say that a 20 gal is too small for that, but as they only get up to about 5" max , they should be OK.

 

[jake37]

In my opinion a large bn is too large for a 20 gallon tank - however for whatever reason some bn are a bit smaller at adult hood (not sure if it is genetic or they are stunted). Having said that there are many pleco that are smaller (closer to 3 inches) including clown, zebra, false zebra, ... and these pleco are fine for a 20 gallon tank.
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Also you can buy a young bn (1 to 2 inches) and it will initially be fine for the tank but if it gets to full size (5-6 inches) then you should consider an option to rehome it. As a frame of reference i purchased 6 lemon blue-eye pleco (actually i purchased 4 but received 6); 3 of the males look like they will be full size; the 2 females look quite a bit smaller (i've had females get over 5 inches but maybe lemon stay smaller or maybe they will fill out in another year); and the 6th male is definitely looking dwarfed for whatever reason.
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zebra are very expensive but the false zebra and clown pleco as well as the mega clown pleco are all reasonably priced. NOTE: not all pleco are algae eater many (majority?) are meat eaters so if that matters to yourself check the diet first - planetcatfish is an excellent site for info on pleco as well as cory.

About the only thing suitable for a 20 gallon tank is a bristlenose pleco and some fishkeepers even say that a 20 gal is too small for that, but as they only get up to about 5" max , they should be OK.

 

[Ikentina]

Welcome to fishlore! Your tank is most likely going through the nitrogen cycle. Do you know about this? I also spy several problems with your stocking Rainbow sharks need at least 55 gallon tanks and get very aggressive, the blue gourami needs a very large tank as well, and the pleco will grow up to two feet, and all the tetras and rasboras need groups of at least six. I would recommend rehoming the pleco, blue gourami, rainbow shark, and choose one or two type of schooling of fish to keep and get your numbers up to six.
Is the dwarf gourami dead? Doesn't look very alive in the photo

Hi, Ikentina. Welcome to Fishlore!

As mentioned above, you've got quite a lot going on in the tank. The common pleco and rainbow shark both need larger tanks. With the current inhabitants, the pleco, in my opinion, should be rehomed as soon as you can. I'm assuming the rainbow shark is still very small since you just got it. But, it won't stay that small long and they do tend to be a more aggressive fish.

Is there any one of the fishes you have that you are finding you like more than all the others?

You mention you are having trouble keeping your ph balanced. What do you mean by that? Are you seeing big swings? Are you adding something to try to raise/lower the ph?

As far as the ammonia... how long have you had the tank running? You say the pleco started at 2" and is now 6" so I know you didn't set it up last week. Other than the rainbow shark, have you added any other fish recently? You have a pretty big bioload going. Reducing the feeding and vacuuming will help, as will rehoming the pleco.

My guess is, if the tank was previously cycled, you've overwhelmed your cycle by adding too many new fish too soon and/or you've stocked too much and the cycle can't keep up.

I previously asked if there was one of the fish types you have that you're preferring, as you might consider going with one particular kind. Depending on what you choose to keep, if you want input on help with the stocking, there are people here that are great with help on stocking a tank.

Regardless of what stocking you decide to go with, lots of water changes (of course with a dechlorinator if your source water has chlorine), reduced feeding, and rehoming the pleco will help right now.

Also, out of curiosity, what is the ph and ammonia of your source water? And what type of filter(s) are you running on the tank?

Dear Aquababy Fishgirl NoRoomforshoes and others, Thanks for your response, sorry for the delay. I’m running an Aqueon 30 on my 20 long. Water source has 0 Ammonia and 7.0 pH. I use Stresscoat to get rid of the Chorine and let it sit at least 15-30 mins. It’s not a new tank cycling issue as tank has been established for 16 months...However Aquababy, I think you hit the issue head on by stating that it could also be the biomass (overstocking) that is overwhelming the Nitrogen cycle (good observation about the growth of the pleco). Yesterday Ammonia was 0.25 ppm, pH 6.0, Nitrites 0 Nitrates 40 ppm (30 ppm today after 33% vac/water change). pH is the most constant problem...6.0 most days... I put baking soda solution to bring to 6.2 next day back to 6.0! Lost my 1 Rainbow and powder blue Gourami and the last of 4 Serpae Tetras over the last 2 weeks (Ironically the Dwarf Gourami still surviving the swim bladder disease...6 wks now!) Not clear if there’s anything that I can do about that. Assuming it was a combo of too much biomass and over feeding in the tank, I rehomed my pleco today. He weighed more than all my remaining fish combined! Think I will take Noroomforshoes advice and NOT use fish to clean the bottom of my tank! So I’ll skip the corys . I do vacuum 1-2x/wk (each time with a 33% water change (would love to get that down to once!) My manual vac takes out so much water that I can only vacuum 1/5 of my tank before 1/3 of my water is gone! Eheim battery vac clearly does not have great reviews with respect to suction power. I have measured the depth of my gravel to be 1.5”...Any other suggestions for a vacuum that takes out less water or no water?

I’m now down to 1 dwarf gourami, 2 Harlequin Rasboras, 3 glowlight tetras and 4 neon tetras. With the pleco gone I’ll just get one Clown Pleco (will grow to max 3”?) for Algae Eating, then I wait a few weeks to reasess. Might like to add 3 red velvets eventually. Over feeding is still an issue as my Dwarf has to exert so much energy swimming up to eat off the surface that I’ve been feeding 3 very small meals a day so he can get 2-3 bites per feed. Spends the rest of the day at the bottom.

 

[Candace]

Dear Aquababy Fishgirl NoRoomforshoes and others, Thanks for your response, sorry for the delay. I’m running an Aqueon 30 on my 20 long. Water source has 0 Ammonia and 7.0 pH. I use Stresscoat to get rid of the Chorine and let it sit at least 15-30 mins. It’s not a new tank cycling issue as tank has been established for 16 months...However Aquababy, I think you hit the issue head on by stating that it could also be the biomass (overstocking) that is overwhelming the Nitrogen cycle (good observation about the growth of the pleco). Yesterday Ammonia was 0.25 ppm, pH 6.0, Nitrites 0 Nitrates 40 ppm (30 ppm today after 33% vac/water change). pH is the most constant problem...6.0 most days... I put baking soda solution to bring to 6.2 next day back to 6.0! Lost my 1 Rainbow and powder blue Gourami and the last of 4 Serpae Tetras over the last 2 weeks (Ironically the Dwarf Gourami still surviving the swim bladder disease...6 wks now!) Not clear if there’s anything that I can do about that. Assuming it was a combo of too much biomass and over feeding in the tank, I rehomed my pleco today. He weighed more than all my remaining fish combined! Think I will take Noroomforshoes advice and NOT use fish to clean the bottom of my tank! So I’ll skip the corys . I do vacuum 1-2x/wk (each time with a 33% water change (would love to get that down to once!) My manual vac takes out so much water that I can only vacuum 1/5 of my tank before 1/3 of my water is gone! Eheim battery vac clearly does not have great reviews with respect to suction power. I have measured the depth of my gravel to be 1.5”...Any other suggestions for a vacuum that takes out less water or no water?

I’m now down to 1 dwarf gourami, 2 Harlequin Rasboras, 3 glowlight tetras and 4 neon tetras. With the pleco gone I’ll just get one Clown Pleco (will grow to max 3”?) for Algae Eating, then I wait a few weeks to reasess. Might like to add 3 red velvets eventually. Over feeding is still an issue as my Dwarf has to exert so much energy swimming up to eat off the surface that I’ve been feeding 3 very small meals a day so he can get 2-3 bites per feed. Spends the rest of the day at the bottom.

I'm sorry about your losses. I recommend not getting another pleco or any other fish until you figure out your stock and stabilize your tank. An unstable and uncylced tank can quickly kill fish (especially clowns based on experience). And one of the best algae eaters out there are nerite snails, even if you had 3/4 the bioload would be less than the clown pleco. You need to stop adding different kinds of fish. I recommend narrowing it down to 1-2 mid-tank schools or tetras and/or rasboras (one school of 10-12 fish or 2 schools of 5-6 fish) since all of the fish but the gourami need schools of 5 or more, and then you could look at a shoal/school of bottom feeders (like corys) or the pleco.

Using my 20g Long tank as an example I have a powder blue gourami, 7 glowlight tetras, 6 bronze cory's and am planning on adding 4 kuhli loaches and that's alittle over what I consider fully stocked. Before I'd decided on the loaches I was thinking about 5/6 neon tetras but I need the loaches to aerate my sand substrate for the plants I'll be adding soon. Unfortunately a 20g long is a smaller tank so stock volume is limited, I know it's hard to pick because of all the choices but having a bunch of mix matched schools in an overstocked tank is just going to stress out any fish you have in there.

EDIT: If that is swim bladder in your gourami it's unlikely that it will get better. I had a betta recently pass away after having swim bladder for 2 months (I didn't have the heart to put him down). I don't believe there are any medicines for swim bladder. ALSO just leave the pH alone, as I was recently told, even if it's not in an ideal range fish will handle that better than trying to alter/adjust the pH suddenly. They'll get used to what ever pH your tap/bottled water is.