General Advice For An Amateur - Tropical Tank

[Tia's Treasure]

Hello to all existing members and a thank you in advance for all your sincere advice and guidance. Just to set the scene, I have a beautifully crafted 2.5ft square coffee table tank, which has water level depth of 1 ft. The tank has a full under-gravel filteration system, two submersible pumps, 4 lights, a heater and themometer.... I hope this paints the picture ; -)

I have had the tank running for over a year now and the initial set of fishes that I put in there a year ago was a batch of Rainbow Plaities. These reproduced and we continue to home the second or third generation siblings! Also our Pleco was purchase around the beginning, when it was a baby (size of my index finger) and today has grown to approx. 6-7 inches long!

Today we currently have the following fishes in the tank:

1 Pleco (1 died in the first week as we bought two together - but have still not found the corpse!!)
3 Cardinal Tetras (4 died within a month of purchase)
Lots of Rainbow Plaities
6 Balloon Mollies (reduced from 11 - again seem to be dying every so often (no trend?!) but I feel its females post birth?)
3 Clown Loaches (lost one last week, one week post purchase??)
3 Orange Mollies
3 Swordfish Mollies

We initally had some lovely real-wood and real plants in the tank but did not work great due to the pleco eating on the wood and polluting the water quickly so now we have a few small real plants and some fake ornaments and plants dotted around.

MY ISSUES ARE:
1. Over the year, why would we be loosing fish regularly? Water is taken to local pet store and tested ok. Temp is maintained at 27-28*C
2. Where could the second pleco have disappeared to that even our regular tank cleaner could not find trace of when he first came to clean 3 months ago (6months post the pleco going missing)...?
3. One of my pumps is currently not operating 100% and I have also moved the coffee table tank to centre-room from the corner, where it has lived for the year. Also, I have done a thorough clean of the tank including 50/60% water change (normal water changes I do are 30% average weekly)and removed the last wood log which the pleco hibernated under... SINCE I have noticed the pleco stuck to one wall of the tank but frequently flipping over to the surface and back (looks like its for O2?) Is there a problem/ risk here??

Apologies for a very long narrative, but I appreciate there are a number of factors and variables that you professionals would need to cover, so I have tried to anticipate these above. Should you need further clarity let me know and I look forward to some advice on the 3 issues highlighted above - THANKS!

 

[CrazyAirborne]

well after using the calculator, and based on ur given dimensions, the tank is roughly 170L or 47 US gallons. thats the first thing people are going to ask.

hmmm.

the only things im going to mention (as im no expert)

You really should invest in a liquid reagent type water test kit. they will really help u see what levels are in your tank. API Freshwater Master Kits are regularly suggested on here.

undergravel filters are becoming less and less common. most people dont use them anymore, but i can understand it in a coffeetable tank. i bring this up because maybe u arent getting enough biological filtration (since u said one of ur pumps isnt working 100%)

depending on the pleco species, he might outgrow your tank and you could consider selling him or giving him to someone who can house him better. also if he prefered to hide under logs, why would u remove all his logs?

ive read mollys do best in a slightly salt water setup. something for u to research and think about.

as far as O2 goes, idk how coffee table tanks work, but if its pretty well sealed on the top of the tank, u will probably need some type of air stone or something in there to give better aeration?

im sure more will come along to help u.


good luck and

 

[KISSfn]

Your temp of 82F may be a little high for the Pleco, Platies and borderline for the Mollies as the recommended temps for your fish are Pleco 70-73F, Tetras 75-84, Platies 68-79, Molly 70-82, Loach 77-86. Maybe the Pleco was very well hidden when he perished. If so I would think his tankmates probably would have eaten him and his decomposition would have added an extra amount of dangerous ammonia to your water.

 

[Randi]

Definitely sounds like O2 is your issue. Not sure how to address this since the tank is in the center of the room and can't have external hardware. Also, plecos need to chew on wood in order to properly digest their food.

 

[adgieman]

battery powered air pump ?