Need Advice Stocking Teachers Tank

[GAB99]

well my teacher has a 55 gallon with a HOB rated for 55/75 tank in her classroom, she was wanting to add more fish in the tank and i took the oppurtunity to ask if i can make a list of good fish choices for the tank. temp is roughly 74 degrees

it currently houses:
1 presumabley stunted goldfish at around 4-5" (presumed since it hasnt grown all year and have heard its stayed that size for years)
1 common plec at around the 6-8" mark
7 rosy barbs, 4 males, three females


now i know this isnt exactly the dream setup but id like to add at least 5-6 more fish in there, ive come up with the following as possible options. based on temprature and with a minimum size of at least 2" save the neons

Gold Barbs
Giant Danios
Threadfin Rainbows
Dwarf Gouramis
Neon Tetras (i dont want them but teacher does so throwing in just in case, considering rosy barbs get 6" long i think theyll become a snack)
Harlequin Rasboras
Swordtails
Platies
Mollies
Emerald Cories
Gold Wonder Killifish

now i dont know if rosy barbs will even have large enough mouths to even eat the neons when they get 6" long but thats highly unlikely, im also skeptical about the rasboras and rainbows as they also have slender body types. i think the platied would be safe if they were aded in now when the barbs are still small, but other then that i think everything else is a good choice. cories id want to not get since theres already a giant plec in there. i am also concerned that the barbs will be aggresive to newcomers but since the males are so busy pestering the females i think it will be fine, though she should add a few more females to level out aggro.


im heavily siding with the swordtails, gold barbs, giant danios, and killifish.

so yeah opinions welcome to help me out

 

[N0body Of The Goat]

• Hopefully others will churp in, but I'd be more worried about the goldfish eating anything bite-sized, more than the Rosy barbs, which definitely rules out the Neon Tetras and young Threadfin Rainbowfish.
• I was under the impression that Rosy Barbs, like Goldfish, need cooler temps than 74F/24C and apparently they rarely reach anything like 6" in the hobby (more likely 4" tops). Something closer to 20C/66F as a regular temp would be much better for them long term, with perhaps a "summer season" max of 22C/70F.
• This sub-tropical temp has a big bearing on the options you gave, which leaves: Gold Barbs; Giant Danios; Swordtails; Platies; Emerald Cories.
• In terms of adding something new that won't intrude too much on the current tankmates, the Giant Danios pretty much pick themselves, but be warned a social group of at least six fish is proably going to strain that HOB filter.
• Some of the fish, including the current Barbs and Giant Danios enjoy current (cannot say I have any idea about Goldfish or Common Plec's preference), so the tank wants something in the 350-450 gallons per hour of filter/powerhead.

 

[GAB99]

well, the goldfish has grown and stayed the same size for the past 4 years, not including this one, and has been in smaller tanks until recently, i would think itd be safe to say that hes gonna stay 4-5", the biggest thing he can swallow would be a pebble slightly larger than the o on the o key. i still aggree thought that neons and threadfins are out though.

ideally yes but even without a heater the tank stayed in the 70s, so it doesnt really make much of a difference either way, i am more concerned with the pleco since that definatley is a tropical fish, temp stats say the it can live in 70 deggree water though but im still concerned.

if the danios require current then id be more inclined to pick the gold barbs or the gouramis as they are more slower flow fish, thought the barbs would probably still appreciate flow.

and if biological filtration is a concern then gouramis and killis would be better suited as the max for both would be 3 killis or 2 gouramis

 

[karin]

Would your teacher be willing to rehome the common plec? I just think that is going to limit things. A filter rated for a 55-75, IMO is very minimal filtration. Ratings by manufacturers seem way over-rated generally speaking. The plec will be fouling the water soon, probably in excess of what the filter can handle. In addition, it is just going to be this huge fish that will seem out of balance with the community members you are considering. Rehoming him you get a lot of bioload freed up to play with.

 

[GAB99]

Would your teacher be willing to rehome the common plec? I just think that is going to limit things. A filter rated for a 55-75, IMO is very minimal filtration. Ratings by manufacturers seem way over-rated generally speaking. The plec will be fouling the water soon, probably in excess of what the filter can handle. In addition, it is just going to be this huge fish that will seem out of balance with the community members you are considering. Rehoming him you get a lot of bioload freed up to play with.

the thing is that fish has been taken to and back the petstore about five times, it was basically free to take it since the chance of it coming back is really high, the guy that sold it said that the tank is in now is the biggest its ever been in so i dont really have the heart to say to give it back.

i remembered i had a few old HOBs im not ever going to use again or at least in the near future, im planning on donating one so that way theres at least double the filtration ( aqua clear 50)


and yes you are right the water is turning a bit cloudy.