Water tests

I just tested my 20g freshwater aquarium and the results are below in pictures. I have 1 angelfish, which I know get too large for a 20g but I cant find another place to put it, 4 cory catfish, 4 neon tetras and 1 hatchetfish(getting a couple more hatchets and neons soon). I was wondering if the water is good for all the fish. The temp is around 78-80F cleaning 10-15 percent once a week. No live plants added yet as I will do in a few days. Every fish, including the angel, get along perfectly swimming everywhere in the tank, sharing food and extremely docile to one another.

The water looks ok.

How long has the tank been set up for?
Has the filter cycled yet (developed the beneficial bacteria needed to keep the ammonia and nitrite levels at 0)?

Do a 75% water change and gravel clean the substrate every week.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Get plants in the tank asap and rinse them before adding to the tank to help wash off disease organisms that could affect the fish. If you don't have a light above the tank, use plastic plants.

If you don't already have one, make sure you put a picture on the back of the tank to help the fish feel more secure.

Lefky said:

I just tested my 20g freshwater aquarium and the results are below in pictures. I have 1 angelfish, which I know get too large for a 20g but I cant find another place to put it, 4 cory catfish, 4 neon tetras and 1 hatchetfish(getting a couple more hatchets and neons soon). I was wondering if the water is good for all the fish. The temp is around 78-80F cleaning 10-15 percent once a week. No live plants added yet as I will do in a few days.

Click to expand...

I'd recommend getting away from the strip tests as they are notoriously inaccurate. Based on those readings, it looks to be okay. You really want to watch the nitrite and nitrate readings. Nitrites should never be above 0 and nitrates need to stay under 30-40 ppm. I would also change at least 25% of the water once a week.

As mentioned, the water params seem okay. I'd suggest you up yer game on water changes to at least 50% weekly to ensure a high quality water chemistry...'the solution to pollution is dilution'. As important as that, 'fresh' water infuses the tank with minerals that are used by both fish and plants.
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Plants are great, but you must have sufficient lighting intensity/duration to support many plants. Anubias and Java Fern are pretty forgiving slow growers. Fast growing floating plants can work with almost any lighting and can dramatically assist in water filtration as they convert pollution (aka nutrients) into plant tissue that is eventually trimmed and removed. Water Sprite is amazing, but there are others. Anacharis is another excellent choice.
With plants you may need some modest fertilization - there are several to choose from Seachem Flourish, Aquarium Coop's Easy Green to mention a couple. Don't necessarily go by the recommendation on the bottle as I find that often half that amount works just fine....matter of fact, and I have some tanks where the water sprite grows like a weed with no [extra] ferts at all.
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There are some that are quite 'fussy' about fish selection relative to species and water params (mostly pH and hardness). I've been in the hobby 50+ years and done my own studies well over 20+ years. With the exception of the more rare 'wild caught' imports, most of the fish we have in the hobby are bred and raised in tanks/ponds with a wide array of different water chemistries. In the community tank, if the fish are active, swimming normally, eating well, and not overly aggressive with any others, they are typically just fine. Just don't mix community fish, with semi-agressive or aggressive species. And don't over crowd your tank!
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As to shoaling fish and numbers, it's recommended to have 6-8 of a given species. I'm not sure who made the 'rule', maybe the same guy that came up with one inch per gallon! IMO, some 'rules' can be bent. For example I have had just two Corys (clean-up crew) in my 60g for the last 9~ years and they are active, healthy, and have little to do with each other.