Pleco & Molly Addition - Possible Issues

Hello all!

I am a small sized aquarium owner, coming in with a 29G tank. This isn't my first ever aquarium, but it has been a while since I had done one before. I went through all of the proper steps of starting this one up: Proper fishless cycle for about 6 weeks, good levels on everything. My pH isn't perfect, it's at 7.5 and I have added some plants to try to balance that out.

My concerns are coming in with the two new additions to my tank. After my fishless cycle, I was actually growing a tad bit of algae. Nothing spectacular, but I figured I could get a small pleco. I picked out one of the plecos that won't grow more than 3-4" on purpose since it's a 29G tank, and then I got a black molly to accompany it. These are my first 2 fish in the tank. I also followed the proper accumulation process.

My skepticism arises from both of their behavior. I have plenty of hiding spots for them, lots of rocks, gravel, plastic and real plants, but they are behaving oddly in comparison to fish I've had in the past. The molly just hangs out by the heater and the pleco hides altogether. I didn't turn the lights on for 4 hours after the accumulation process, but when I did the pleco dug deeper and it keeps pushing up against the lava rock I have in there. It has stayed toward one side of the tank altogether, and will not eat any of the algae in there or the algae wafers I have put in there. I even tried sticking them to the side of the tank to see if it would come and grab them. It has been about 12 hours, so I attributed this to it just being in a new place.

The molly ate at first but now it just won't move. My temperature is at a nice 78F, so that's what throws me off about it almost hugging the heater. I have the thermometer on the far side of the tank from the heater so I can guage that it's an even 78F throughout.

Should I be concerned, or am I just paranoid?

 

What are your water parameters?
Using API liquid test kit is more accurate.

7.5 ph isn't bad most fish are adaptable to ph.

What are your gh and kh?

What type of pleco do you have?

Pictures are always nice.

 

Plecos need real driftwood in the tank to rasp on. If it is a clown pleco , they are more nocturnal than some. They also need time to settle in to a new tank and get comfy. Alison

 

I will send pictures when I get home. As mentioned previously, all water parameters are proper aside from pH. I used an API liquid test kit to determine that.

I am nervous about the molly just being by the heater. When I get home I will confirm whether it is a male or female, as I have read online that I may have received a pregnant female from the store.

The pleco is indeed a clown pleco! I will get it some driftwood right away, hoping that I can find some reasonable stuff that won't leech tannins badly.

 

MopanI and grapevine tend to leach more tannins , I bought preplanted Malaysian driftwood ,it has anubias planted on it, for 14.98 out of the tank at Pet Supermarket, The only thing I did was check for snails and put it right in my tank. No presoaking or prep. Is this you first pleco or have you had them before? Do you know what to feed them.? ...Alison

 

Welcome to the forum

Exact water parameters would be helpful for ammonia, nitrite, nitrate so we can rule out any water quality issues. Have you added any other additives to the tank besides your water conditioner during water changes?

 

Hello Ping...

Mollies aren't small tank fish. They're too aggressive if they feel cramped at all and smaller tanks can't really be kept clean enough to suit them. Mollies also have some pretty specific diet requirements. The Pleco, depending on the species, can grow quite large and any larger fish isn't suitable for a small tank.

You'll have a real challenge keeping these fish.

Good luck.

Old

 

The clown pleco will be fine in that tank just make sure you get the driftwood.

 

Thank you for all of the replies. The mollies are fine in a 29G tank. That's probably the minimum size it can be for them, but they are fine in it as long as I don't get too many of them. I've been following the guidelines on aqadvisor.

I did get them to behave better. The clown pleco is just a little nervous, especially when I come in the room. I ended up getting a few more fish including a redtail shark. I made sure my water parameters met expectations, and ammonia is still at 0ppm. I now have 6 fish, and it will stay that way since my filtration is around 60% out of it's total capacity, and I would rather it be able to filter way more than be overwhelmed. I have 2 dalmation mollies and 2 black mollies, the clown pleco, and a rt shark. If I need to move the mollies into a 55G planted I am starting, then I will presuming that fishless cycle goes fairly quickly (it should since I will be sharing media).

The mopanI driftwood I purchased is leeching tannins a little bit, even after I let it sit in water for a while and it didn't look like it was changing the color. I did notice a faint smell yesterday, but again, my levels are all fine. I didn't know if tannins could cause this or not. I was worried about it being new tank syndrome, but it really can't be as my bacteria is doing well, and my java fern isn't doing poorly either. I could possibly have overfed a bit yesterday in worrying that the clown pleco would starve himself to death as well as worrying about the newly-added fish not getting food for a long while prior to purchase.

I skipped feeding them this morning since I read that they can go 2-3 days without being fed, and this will help re-adjust any of the overeating habits (I was going to skip a half day and do a water change when I get home).

Also, I gave my pleco some cucumber the other night when I turned off the lights, and it seems it had absolutely no interest in it. The pleco also hides under the mopanI wood more than it lounges on it, unfortunately.

 

That is normal pleco behavior and he is still new to the tank It also can take a couple of tries or even more to get them into trying their veggies. And the clown is more likely to eat it after the lights are out. They should have a piece of fresh veggie or fruit in the tank on a 24/7. availability. That is in addition to algae wafer and other foods. In the current thread titled Plecos!! share yours, I wrote a post on feeding BN plecos their fruits and veggies and other fruits. The same thing applies to the clown pleco. It is on page 3 about halfway down the page and then was reprinted again in a quote on page 16. Please give it a read to give you some ideas and hints. ..Alison

 

My clown Pleco hasn't come "out" in over a month, but I have a ton of driftwood set up like a cave so I suppose there is no reason for him to... I do catch glimpses of him each night when lights go out and veggies are added... Seems to like the zucchinI more then the cucumber...
Also, for the tannins, be sure to keep checking your pH, they can lower it a bit. To get rid of tannins in water I added Purigen into a filter...worked wonders! However, some products react with Purigen so you have to be careful if using amine based products (prime is totally fine)

 

My clown Pleco hasn't come "out" in over a month, but I have a ton of driftwood set up like a cave so I suppose there is no reason for him to... I do catch glimpses of him each night when lights go out and veggies are added... Seems to like the zucchinI more then the cucumber...
Also, for the tannins, be sure to keep checking your pH, they can lower it a bit. To get rid of tannins in water I added Purigen into a filter...worked wonders! However, some products react with Purigen so you have to be careful if using amine based products (prime is totally fine)

I didn't want to add Purigen just yet as I don't like messing with chemicals, and I don't want to reduce any bacteria. I worry myself with ammonia so I want to keep the bacteria as in-tact as possible for the time being since I may have overfed a bit and the mollies poop quite a bit. I will definitely get some and add it in within about a week or so, though. Thank you for the addition!

That is normal pleco behavior and he is still new to the tank It also can take a couple of tries or even more to get them into trying their veggies. And the clown is more likely to eat it after the lights are out. They should have a piece of fresh veggie or fruit in the tank on a 24/7. availability. That is in addition to algae wafer and other foods. In the current thread titled Plecos!! share yours, I wrote a post on feeding BN plecos their fruits and veggies and other fruits. The same thing applies to the clown pleco. It is on page 3 about halfway down the page and then was reprinted again in a quote on page 16. Please give it a read to give you some ideas and hints. ..Alison

I will definitely check this out. I love the plecos. Thank you!

Is 24/7 really necessary for them to have veggies or fruit? The other guys I have in there will dig at just about everything. I did notice my pleco hiding and hoarding algae wafers yesterday, and it became very defensive of a specific area under the driftwood. However, as soon as he moved (sort of chased the rt shark out of his area), the mollies came in and started eating the wafers. I felt bad for him. I do know that if I have veggies or fruits in there for a long while, everyone will eat them before him even if I put them in when I turn the lights out.

I see so many recommendations for 24/7 fruits & veggies and yet I see so many other things saying to remove uneaten food after only a few minutes. Is there one piece of advice to actually follow here? I notice everyone has a point of view, so there are often a lot of different contradictions in the fish world.

 

Hmm. Not too keen on mollies being in a 29 gallon honestly. It's a bit snug for them and they'd thrive better in the 55g.

 

A piece of raw veggie doesn't deteriorate like fish food does. Yes it should be available 24/7. When a pleco eats food, what goes in comes out as poop 45 minutes later. They are grazers and meant to eat on and off and nap in between. Their digestive system is a lot different than say people and other animals and even other fish. Alison

 

I didn't want to add Purigen just yet as I don't like messing with chemicals, and I don't want to reduce any bacteria. I worry myself with ammonia so I want to keep the bacteria as in-tact as possible for the time being since I may have overfed a bit and the mollies poop quite a bit. I will definitely get some and add it in within about a week or so, though. Thank you for the addition!

Purigen doesn't affect your cycle so it's safe to add to your filter and it works just like activated carbon but better to remove discoloration in the water and other impurities.

That's a lot of fish to have added at one time not to mention they are huge waste producers so you risk overwhelming your beneficial bacteria. I would monitor your water parameters very closely the next few days and make sure your ammonia and nitrite are zero while keeping nitrates below 20ppm. I agree that moving a couple of mollies and the RTS (which are not appropriate for a 29g) to the 55 gallon once it's set up is probably a better idea.

 

Purigen doesn't affect your cycle so it's safe to add to your filter and it works just like activated carbon but better to remove discoloration in the water and other impurities.

That's a lot of fish to have added at one time not to mention they are huge waste producers so you risk overwhelming your beneficial bacteria. I would monitor your water parameters very closely the next few days and make sure your ammonia and nitrite are zero while keeping nitrates below 20ppm. I agree that moving a couple of mollies and the RTS (which are not appropriate for a 29g) to the 55 gallon once it's set up is probably a better idea.

Okay this is one of those additional times where there are quite a bit of contradictions. Based on so many posts on the forums, and really all over the internet as well as Aqadvisor, I was told that a 29G is perfectly fine for the RTS and the mollies, albeit that the 29G is probably the smallest size that works for them. I don't want to have to add them to the 55G, but I will if it's a necessity. I just get so many conflicting responses. Same thing with Purigen, that it will indeed kill off beneficial bacteria. I believe I watched a video on YouTube from Jacob's Aquarium where he mentions that as well.

 

Welcome to fishlore!!

I am confused as to why you added 3 more mollies when multiple people were telling you that the one you already had was really not appropriate for a 29?

I think it is great that you spent all that time cycling your tank with a fishless cycle (that takes major patience!), but now that you have added all those messy fish at one time, you will likely have a minI cycle to deal with. I would suggest doing water changes every day, or every other day for a bit. Basically, you might as well have done a fish IN cycle at this point. (ok maybe that is a bit extreme lol but still, your ammonia and nitrites will likely go up for a bit)

You did do everything properly....until you chose the fish you chose and added them all at once. As others said, a red tail shark is definitely not appropriate for a 29 either. So I hope you get that 55 gallon up and running quick for the sake of all those fish!! The mollies and the shark should definitely go in there. And then you can stock the 29 more appropriately.

 

Pleco & Molly Addition - Possible Issues

Same thing with Purigen, that it will indeed kill off beneficial bacteria. I believe I watched a video on YouTube from Jacob's Aquarium where he mentions that as well.

Not true. I've used Purigen for a year and had no ill effect on the bacteria or the cycle. However, adding too many fish with high bioloads do risk overwhelming your bacteria.

Aqadvisor isn't completely reliable for stocking.

 

Not true. I've used Purigen for a year and had no ill effect on the bacteria or the cycle. However, adding too many fish with high bioloads do risk overwhelming your bacteria.

Aqadvisor isn't completely reliable for stocking.

Sounds good. I will deal with the tannins for now as there's a lot of conflicting information all over the internet with that, and I don't mind them for the time being, especially since my bioload is larger now and my bacteria needs to rebuild.

I will probably move the RTS into the 55 within a month or so. I don't want to rush that cycle in the 55, or stress the RTS out too much more. Right now it is very small and it seems like it actually enjoys the company of the mollies, so I will keep them in their current location for the time being.

I really think an issue I may have been having originally was oxygen. My filter is a hangover and it does spill into the water some, but I do think I will need to get an air pump (presuming I can find an inexpensive one with an option to be set to low). I don't want too many bubbles, nor do I want the sound to be too much so long as I can increase my oxygen a little bit. I am very minimal on plants at the moment, so my oxygen is not high.

Will the molly bioload help with the 55 gallon planted tank in the future?

 

I really think an issue I may have been having originally was oxygen. My filter is a hangover and it does spill into the water some, but I do think I will need to get an air pump (presuming I can find an inexpensive one with an option to be set to low). I don't want too many bubbles, nor do I want the sound to be too much so long as I can increase my oxygen a little bit. I am very minimal on plants at the moment, so my oxygen is not high.

Will the molly bioload help with the 55 gallon planted tank in the future?

As long as your filter output creates some surface agitation, that should be enough. If you feel like the fish need more, then you can add an air stone.

I'm not sure what you mean by that last question? Are you asking if the bioload of the mollies would provide enough nutrients for your plants without the use of ferts?

 

That is exactly what I am asking. The plants are low tech, low-moderate light plants.

 

If they are low tech, low light plants, then yes, they should do ok with the waste from fish alone. If you really want to see some of the plants take off, then liquid ferts, root tabs (for root feeders) and liquid CO2 would help.

 

el337 I love tour pleco food tips! Anyhow, as per your plecos behavior OP, if you haven't had one before they will be a little weird until they find their hiding spots and settle down. I don't know if it was stated as this thread exploded while I was trying to read it.. The pleco will eat algae but it will also create a lot of waste. I know el mentioned the grazing habits earlier. So that will stress the bio of the tank in addition to all those fish you added on top. I would keep the pleco and rehome the rest (especially the shark) and come up with a new game plan of tank mates and add them slowly over time.

 

el337 I love tour pleco food tips! .

Wasn't my post. That credit goes to aliray.

 

@el337 I love tour pleco food tips! Anyhow, as per your plecos behavior OP, if you haven't had one before they will be a little weird until they find their hiding spots and settle down. I don't know if it was stated as this thread exploded while I was trying to read it.. The pleco will eat algae but it will also create a lot of waste. I know el mentioned the grazing habits earlier. So that will stress the bio of the tank in addition to all those fish you added on top. I would keep the pleco and rehome the rest (especially the shark) and come up with a new game plan of tank mates and add them slowly over time.

Thank you! That's the plan. I have tried to accompany to the pleco while its been shy. It started hiding behind the filter, and I knew that this behavior was due to insufficient hiding spots. I have provided more spots since, and an additional filter to handle any bio load issues. I'm not running an Aqueon QuietFlow 30 and a Fluval AquaClear 20. I had the QF media tested at the store today, and they said from what they can tell the bacteria is strong, although the bioload will be challenging for it. I shared media between the 29G and the 55G the other day, and I tested it today and it seems that the cycle is doing very well. Thanks for the advice!

 

Thank you! That's the plan. I have tried to accompany to the pleco while its been shy. It started hiding behind the filter, and I knew that this behavior was due to insufficient hiding spots. I have provided more spots since, and an additional filter to handle any bio load issues. I'm not running an Aqueon QuietFlow 30 and a Fluval AquaClear 20. I had the QF media tested at the store today, and they said from what they can tell the bacteria is strong, although the bioload will be challenging for it. I shared media between the 29G and the 55G the other day, and I tested it today and it seems that the cycle is doing very well. Thanks for the advice!

Right now (because I wasn't able to grab a 29 gal during sales) I have a Young BN in a 20 gal with a Quietflow 30 with ceramic rings added to it. Mine hides behind the filter, but has plenty of others spots to hide. He has one spot I haven't figured out yet so he goes missing time to time lol. Make sure you do water changes often. I do 25-50% changes weekly but also I'm about 10 gals shorter than you. Just plan your tank mates around the BN bioload wise if you want to keep it. I used to do a no no and raise commons in my 25g and sell or trade them when they hit 4-5inches. Bio load can be kept up with as long as you don't get lazy lol. I went out of tow.n last weekend and was a few days late on my cleaning and water change. You could tell. Otherwise my waters crystal clear. I do have new tank syndrome where I have diatoms, but my pleco surprisingly eats it.. Lol

 

Right now (because I wasn't able to grab a 29 gal during sales) I have a Young BN in a 20 gal with a Quietflow 30 with ceramic rings added to it. Mine hides behind the filter, but has plenty of others spots to hide. He has one spot I haven't figured out yet so he goes missing time to time lol. Make sure you do water changes often. I do 25-50% changes weekly but also I'm about 10 gals shorter than you. Just plan your tank mates around the BN bioload wise if you want to keep it. I used to do a no no and raise commons in my 25g and sell or trade them when they hit 4-5inches. Bio load can be kept up with as long as you don't get lazy lol. I went out of tow.n last weekend and was a few days late on my cleaning and water change. You could tell. Otherwise my waters crystal clear. I do have new tank syndrome where I have diatoms, but my pleco surprisingly eats it.. Lol

I think I am starting to get a diatom thing going on. We will see, but it isn't bad as of yet. Mr. pleco is very lazy and hasn't eaten much that I have seen. Most of my current bio load is from the mollies, although the 2nd filter has been chomping away at it and the tank is looking super clean.

My new dilemma is the inside glass in the tank. It's getting nasty and I clean it with a brush, but it doesn't really do much. Any suggestions on a fish that would clean up this surface a bit? Or do I need an algae brush specifically? I'm not even sure if it's algae.

 

Can you take a picture of the algae or whatever you're seeing on the glass? I wouldn't get more fish to take care of that problem.

 

Can you take a picture of the algae or whatever you're seeing on the glass? I wouldn't get more fish to take care of that problem.

It's not really visible on my camera. It looks like smudges almost to the naked eye, and when I feel it with my hands it is definitely slimy. I don't remember this when I kept fish in the past, although I may have neglected things more back then. I was presuming its algae due to its surface or it is a diatomic growth that hasn't shown any color yet. The same feel is on my plants and decor, but it is not visible at all.

 

It's most likely diatoms. You can just scrape it off with one of those mag float scrapers that work really well. Diatoms eventually go away on their own.