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Im a beginner, have a 20 gallon tank which cycled for 5 wks (fishless cycle) gravel, fake plants, whisper air pump and Aqua clear filter rated for up to 40 gallons. Added 2 zebra and 1 leopard danio at first, after 2 wks added 3 rosy danios, another 2 wks added 5 dwarf corydoras.
So can i add more fish, i know about the "the rule of thumb" but with adequate filtration, proper maintenance and regular partial water changes.

Ammonia - 0
Nitrite - 0
Nitrate - 5
pH - 7.2
Temp - 24 deg Celsius
Use Nutrafin liquid test kit. I do weekly 25% water change.
Have not had any casualties since introducing fish. Tank has been running for 2 months now.

By the way thanks guys used this site as my main source of information for starting fishkeeping.
Hi Inno, welcome to the forum. Welcome

What source of ammonia did you use for your fishless cycling?

If you used more than 4~5ppm ammonia daily to finish your cycling, it is not required to add a few fish at each time after the cycling was already completed. I fully stocked my 40 gallon tank with 30 or so fish at once. No problem at all, because I know the amount of ammonia I added for fishless cycling was more than a fully stocked tank can produce.


Those Danios need to be in larger group. It is recommended to have minimal 5~6 for each species. As you have 3 separated species, you need total 9 more to make group of 5 for each of them.

However, since you already have 11 fish in a 20 gallon tank, you don't have too much room left. If you really adding 9 more fish, it makes total 20 fish, even they are small size fish, you will need to increase the weekly partial water change to more than 30% to keep nitrate down.
Thank you Ram, i live in Canada so i used Old Country Ammonia from Home Hardware. 5-10% ammonia and rest is water according to email i got from the manufacturer.
Anyway i added fish slowly because i was scared and thought the bio-load would be too much for my tank. I was dosing 4ppm for my cycle.
Even though i have 3 separate species of danios, i just assumed since they all danios they will be fine.
They do swim together though.

I do have a 15 and 40 gallon (not cycled yet) that i just got from my neighbor. Want the 40 with real plants but still gathering info on lighting and C02.
You will need T5HO lighting as well as good substrate if you are serious about having a planted aquarium. You can see my planted aquarium in my signature with all equipments listed except for CO2.

I am still testing around with CO2, and current CO2 is just DIY.

If you have never used CO2 before, it is a good idea to try out something cheap first before throw a lot of cash on a standard system that can cost a fortune. Try something cheap like Fluval Pressurized CO2 Kit.

In my experience, CO2 does make my plants grow faster. The biggest problem with a heavily planted tank is algae covering and killing plants. The only true way to keep the tank looking excellent is to keep trim away and replant the top very often. CO2 can help plants outgrow algae.
I am subscribed to your channel on youtube if you are Vash6the6Stampede.

I have never used CO2 before and everything about planted tanks is still new to me. I plan on using Eco-complete substrate, do i use it by its self or add fertilizer to it for the pants.

Bought an Eheim Ecco Pro 2234, instead of the classic as replacement parts are hard to come by nowadays as per local LFS. set me back a little bit, they are not cheap.
Do the lights need to stay on 24/7 for live plants ? sorry for the million questions.
Yes, that's me.

Replacement parts for the EHEIM classic series are available online, but I agree some of the newer versions are easier to clean. They come at higher price.

You should never leave lights on more than 12 hours a day. Unless you want an algae boom. Most planted aquarium owners do not leave their lights on for more than 8~10 hours a day. Once algae cover up the plants, the plants will die because they can't receive the lights. The tank water might also turn green. Even fish will go crazy if there is daylight all the time. Try to use an automatic timer to turn on/off your lights at the same time every day.

If you are really going for a planted aquarium, I would suggest you to set your 40 gallon up, and plant the plants before start doing a fishless cycle. Plants do need a head start, in case some fish might like to unroot them.