AboutMichael Freynet Expertise I can answer most questions on freshwater aquariums involving the biological cycle, live plants, fish compatibility, stocking quantity, feeding, filtration, aeration, water chemistry, and cleaning. I am still learning about some certain diseases and parasites but am more than willing to research any questions that I do not know.
Experience I have owned multiple freshwater fish tanks over the years. I also help maintain other people’s freshwater fish tanks. I am currently a college student at Minnesota State University Moorhead for a major in Biology and a minor in Zoology. I'm also currently employed at Petco.
Question I just set up a 20 gallon tall (24 inch) tank. It contains a back filter, heater, plant appropriate gravel (I forget the name), and 4 live plants and 2 fake ones. Lights are on 14 hours/day, heater is set to 72 - but due to the weather the temp stays at ~76 right now. I have put 2 "starter" platies - they have been there a week and seem to be doing very well. I would like to stock the tank with platys as well as neon or cardinal tetras ... do you have suggestions for optimal stocking with those fish?
I used to have a yoyo loach in a 20 gallon tank who did really well for 5 years (before internet days) - but now I read that I shouldn't keep loaches in a 20 gallon tank? I would like to have ~4 different species?
Do you have a suggestion for a good book on aquarium up-keep? I have a book I love called "Your Home Aquarium" by Jorg Vierke from many years ago that is quite helpful - but outdated I'm afraid. It recommends ~33% water changes every month - and it seems that the current recommendation is 25% weekly?
Thanks,
Colleen
Answer Hello Colleen,
I'm glad you decided to take the time to question me on your concerns. A lot has been learned in the aquarium hobby over the last few years and to stay updated with the facts is always good. Remember the general rule for tropical fish is one inch of fish per one gallon of water. If you over populate you are risking the lives of your fish in many ways as in water pollution through toxicity(ammonia/nitrites/nitrates) and general stress due to the cramped environment. A stressed fish is not a healthy fish. Being as how Platies/Neon and Cardinal Tetras/Yoyo Loaches are all tropical fish you would be better off with a warmer water temperature of around 78 degrees. The warmer water would speed up their metabolism which would make them less likely to get disease and sport better coloring.
Now keeping in mind the one inch of fish per one gallon of water rule you may have to rethink what you should get for your tank. A Yoyo Loach(I actually have three of them right now in my 46 gallon) stays at around 4 inches at adult size and a 20 gallon tank would suit one just fine. I would possibly reconsider getting one though as they do enjoy the company of other Yoyo Loaches and say hypothetically you got two of them it would only leave you with 12 gallons of water for stocking other fish. I think a more suitable replacement for a bottom feeder would be like a trio of Corydoras(I would have at least three as they are schooling fish). They stay fairly small, come in many patterns varieties, are peaceful, and are excellent at eating the flakes off the bottom. They usually top out at around 2 inches and there are even some dwarf species that stay at around an inch(panda and pygmy Corys).
An example of a good community set up could be:
three Corydoras = 6 inches
two Platies = 6 inches (make sure you get two females)
eight Neon/Cardinal Tetras = 8 inches(you can mix them)
That would put you at 20 inches for 20 gallons of water and would safely max out your tanks bio load capacity.
As for water changes for the first 5-7 weeks while your tank is establishing itself I would take out 25% of the water every seven days. After the acclimation you can keep doing that or do 30% every two weeks minimum. Keeping up on your frequent partial water changes will save you tons of trouble down the road. Although I don't know of any books in particular for you to purchase, know you are free to ask me whatever questions you'd like whenever.
