Stocking Advice - Medium (?) Hardness

[Rebecca999]

Hi everyone,
Am happy my first tank is properly cycled and am about to start stocking slowly.
I'm unsure if I should be going for hard or soft water fish - parameters seem somewhere in between. It's 57L/15G, have it at 25 deg. and moderately planted up.
Tank
pH 7.6, GH 179, KH 107
Tank after 25% water change
GH 143, KH 90
Tap
pH 7.2, GH 72, KH 36
I'd prefer to go with small tetras, pygmy gourami, endler to start with but are these parameters too hard for them? Okay if I'm vigilant with water changes?
Or would you go with hard water species? If I then went with guppies, is it okay to keep all males to avoid dealing with the fry, or will this create aggression?
Thank you for any advice!

 

[MattW]

Not much experience with those species I'm afraid other members will have a much better idea than me

@CassCats @emeraldking ?

 

[emeraldking]

With your water hardness, I wouldn't go for the gourami and tetras. Livebearers, African cichlids and so on could work with these parameters. But if it's just a 57 liter tank, I wouldn't go for African cichlids either.
An all male livebearer tank can work. Not always, but a hierarchy "can" be developed when keeping an all male tank.

 

[Colin_T]

Something in your aquarium is increasing the pH, GH & KH. Do you have shells, limestone or dead coral in the tank?

You should get 2 buckets of tap water. Add some gravel to one bucket and leave the other bucket with only tap water. have the two buckets next to each other for a few days and see if the gravel changes the pH, GH and KH. The bucket of water is the control so you know what the water by itself has for a pH, GH & KH.

If the gravel doesn't change the water chemistry after a week, put the gravel back in the tank and try testing the ornaments one at a time by putting them in the bucket of water for a few days to a week.

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What are the tank dimensions (length x width x height)?

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Angelfish, discus, most tetras, most barbs, Bettas, gouramis, rasbora, Corydoras and small species of suckermouth catfish all occur in soft water (GH below 150ppm) and a pH below 7.0.

Livebearers (guppies, platies, swordtails, mollies), rainbowfish and goldfish occur in medium hard water with a GH around 200-250ppm and a pH above 7.0.

If you have very hard water (GH above 300ppm) then look at African Rift Lake cichlids, or use distilled or reverse osmosis water to reduce the GH and keep fishes from softer water.

 

[Rebecca999]

Thanks for the advice all, will do some more testing and see what the source is. Have also just realised I probably should have let the tap water sit for 24 hrs before testing, it may be the source of hardness after all.
The tank is 40x32x40ish, 51L, with the back section with equipment sectioned off at around 6L.

 

[Colin_T]

The GH doesn't normally change in 24 hours of coming out of the tap. However, the pH can change 24 hours after being out of the tap.