I know Lupin won't mind my hopping in here to get you started. The first thing I need to tell you is that your tank is way
too small for even 1 Goldfish
much less 3. When healthy, these fish grow quite rapidly.
The red veining in the fins is a warning sign... it typically indicates stress, but that stress can be from moving, from poor water quality, other fish (such as a large pleco harassing them or a bully in the bunch), from water that is too warm, or even from illness. The first thing to do when you notice any red veining in the fins or along the dorsal (back) region, is to check water parameters for ammonia, nitrite, nitrate, and pH. The 2nd thing to check is temp... especially with the fancy variety, try to keep it below 70F.
I am wondering where you found info stating that Goldfish
have no stomachs?
I have been keeping/raising & studying Goldfish
(both comets and fancy) for many yrs. At present I have only 1, his name is Freddy and you can see a photo of him in my aquariums section. As soon as I finish here I will go check to make sure the photo is there for you. Freddy is about 5 yrs old now, and 8 1/2 inches long, which is full adult size for a fancy Goldfish
. Freddy lives in a 120 gallon tank, along with a new small (3 1/2 inch)l pleco that was brought home recently to replace the large one that used to reside in there. The big one was re homed because at 8+ inches, he was getting too aggressive and spent too much time attacking Freddy. Fancy Goldfish
don't swim very fast, so they fall victim to plecos and any other more aggressive fish quickly. Comets are also not good companions for fancy Goldfish
, as they are far too aggressive. A 2 - 3 inch comet can wipe out a full grown fancy Goldfish
in a matter of a couple of days... in any size tank.
I am wondering why your mom is refusing to let you re home your pleco? Have you tried explaining to her that 1 of 2 things is going to happen if you don't.... either the pleco is going to get too big for the tank and die... or its going to attack and eat the new Goldfish
, especially in that size of a tank. Please let your mom know that to keep 3 fancy Goldfish
as adults with a full grown pleco, you'll need well over 200 gallons of tank space to keep them all alive. The 3 Goldfish
, as adults, even without the pleco will need at least 200 gallons.
So, I guess my first advice to you would be to start planning for a much larger home for the Goldfish
asap. If healthy, those fish can double in size over the course of 6 - 8 months. The second bit of advice I can offer is to begin a ritual of daily 10 - 20% water changes (do your water testing before water changes). Be sure to keep good aeration going at all times, and watch closely the red veining in the fins. If it gets worse come back here and let me know and I can offer you some ideas to help until we can determine the actual cause and get it fixed. Goldfish
consume a much larger amount of oxygen than the average aquarium fish, and with 3 of them in such a small tank, that will deplete O2 levels quickly.
Keep them clean, keep them cold, and keep them well fed with lots of veggie based foods and algae wafers. Omega makes a great sinking Goldfish
pellet food, and its offered in different size pellets to accommodate the fish's growth and needs. If you need help finding them I can post a link here for you, just let me know.
I hope this has helped some. There is a lot more to learn about them than what I've put here tonight, but I don't have time to write a manual tonight, lol. I will keep an eye on this post and help get you through the rough spots... but the only way to ultimately "fix" the problem is going to be getting them into a larger tank soon and without the pleco. I don't know where you're located, but apple snails, if you can find them, make good tankmates, and so do trapdoor snails. I have ram's horn snails here, acclimated to the colder water, and they thrive in that tank better than in the warmer tanks.
Best of luck to you and your new friends.