Fish for very hard tap water.

[Ismene]

So I have a 50g with three Pearl Gourami and four Amano shrimp. I’d like to add by some small schooling/shoal fish. Problem is my tap water. Out of the tap nitrates are 40ppm or worse if farmers are fertilizing their fields. Furthermore, my water is ridiculously hard. GH and KH in double digits. All my fish have adapted to this (I also have a 29g). I need a fish that’ll be able to do the same. Suggestions?

 

[Mudminnow]

Most hardy fishes can adjust to hard water even if they aren't found in it in the wild. I personally like rasboras with pearl gourami, some that could work are harlequin rasbora, redtail rasbora, and lambchop rasbora. But, pretty much any fish that has a reputation for being hardy could work.

 

[brhau]

Endlers need hard water.

 

[A201]

My tap is very hard with a 8.2 PH.
I keep Columbian Tetras. Diamond Tetras, Denison Barbs, Filamentosa Barbs, Tiger Barbs & various species of Loaches. No problems.
I believe any of the listed fish would do well in your tank.

 

[BPSabelhaus]

Endlers need hard water.

This.

Small, colorful, energetic.

Just not really schooling/shoaling though.

More like a music festival. There’s a group, with smaller groups / individuals coming and going and a mosh pit of rowdy, colorful boys in a crowd of women there for Sara Bareilles lol

 

[Frank the Fish guy]

Dwarf rainbow fish!

 

[Cherryshrimp420]

I think low stocking is the way to go for your waters. Your tank is essentially a nitrate filtration system. Don't need a lot of fish and plants love it.

 

[jmaldo]

Ismene
You have been given some good recommendations..
Just wanted to mention "Nice" tank!

Good Luck!

 

[Ismene]

Ismene
You have been given some good recommendations..
Just wanted to mention "Nice" tank!

Good Luck!

Thank you!
Thanks everyone for the suggestions! I really appreciate the help

 

[airfix2]

Most hardy fishes can adjust to hard water even if they aren't found in it in the wild. I personally like rasboras with pearl gourami, some that could work are harlequin rasbora, redtail rasbora, and lambchop rasbora. But, pretty much any fish that has a reputation for being hardy could work.

agree but want to add on to this. most fish nowadays are bred in farms that have harder, more alkaline water so they will be used to that sort of water.

 

[ProudPapa]

I also have hard water with pH at 8.2. Serpae tetras, lemon tetras, black neon tetras, and pristella tetras have done well for me, along with three species of Corydoras.

Turquoise rainbowfish have done well also, but you said small fish. They don't qualify (though I think they'd be fine in your tank).

 

[SparkyJones]

"Out of the tap nitrates are 40ppm or worse if farmers are fertilizing their fields. Furthermore, my water is ridiculously hard. GH and KH in double digits."

the nitrates are a problem and will always be a problem, doesn't matter what you stock for fish, and it goes without saying but should be said, but you shouldn't drink it either.

What we need to know is, pH, GH, KH, nitrates of the tap water.
the same tests after 15 minutes of sitting, does anything drop?
the same parameter measures before and after a water change = affects on the tank and between water change "aging".

GH and KH below 4 and over 20 degrees are problematic, but is it really problematic? You are managing to keep shrimp and a gourami (gourami being a labyrinth fish, not such a big deal, but shrimp don't like bad water.) if you are running 11s, technically, you just need a nitrate sink to get rid of those nitrates which would be a crazy amount of plants.

Maybe you need a really slow acclimation process to keep what you want depending on parameters, Most all fish are capable of acclimating over time to water parameters even extremes. Tetras, angels, discus are troublesome with water quality issues, but most fish jsut need enough time to adjust.... but generalization of the situation doesn't paint a clear picture of the issue and can't lead to a solution to correct it.

Maybe you need to rethink the tank set up and do and over under with the 29g, and blow the 29g out with plantings to use up nitrates to supplement the 50g, a nitrate sump and pass the water through the 29g heavy planted tank to remove nitrates for the 50 gallon lighter planted tank, maybe you keep shrimp and snails in the 29g jungle sump to use up some calcium and the plants to use up potassium and phosphates and keep, it becomes a GH dropper as well as a nitrate remover. heavily planted, lightly stocked with small calcium using critters. and your 50g for your fish, after the plants have worked their magic and nitrates are brought down.
If KH is high, pretty sure you could use and acid buffer to lower KH, and it would produce CO2, which would benefit the plants also, maybe you store water in the 29g heavily planted and lightly stocked tank between water changes, and it does the work of cleaning up the nitrates and lowering GH and KH, and you use 25g of that water for water changes when nitrates are low, and re-top it with high nitrate water again. to lower it before the next water change.

Maybe you need a RO/DI filter and build your water after for the aquariums, but if you do, I have no idea how you manage to keep shrimps currently. if you have 11-12 dGH and dKH, its not a big deal. neither will really affect the fish, unless it's affecting the pH and raising or lowering it depending on what the parameters actually are. barring that it's not a big deal, it's the extreme ends of KH and GH that cause problems.

No way of knowing what the best solution is. without knowing how bad the problem really is. but it really can't be that bad if you are keeping fish and shrimp in it. there is a solution though and I don't think it's really all that extreme of an answer.

 

[FishDin]

I think a nitrate "scrubber" using algae in a sump would be an interesting project. You just need to harvest the algae periodically. I've never done it, but have seen DIY tutorials. Same Idea as SparkyJones above, but simpler and cheaper.

You could also use RO water and remineralize.

I like your tank

 

[Ismene]

"Out of the tap nitrates are 40ppm or worse if farmers are fertilizing their fields. Furthermore, my water is ridiculously hard. GH and KH in double digits."

the nitrates are a problem and will always be a problem, doesn't matter what you stock for fish, and it goes without saying but should be said, but you shouldn't drink it either.

What we need to know is, pH, GH, KH, nitrates of the tap water.
the same tests after 15 minutes of sitting, does anything drop?
the same parameter measures before and after a water change = affects on the tank and between water change "aging".

GH and KH below 4 and over 20 degrees are problematic, but is it really problematic? You are managing to keep shrimp and a gourami (gourami being a labyrinth fish, not such a big deal, but shrimp don't like bad water.) if you are running 11s, technically, you just need a nitrate sink to get rid of those nitrates which would be a crazy amount of plants.

Maybe you need a really slow acclimation process to keep what you want depending on parameters, Most all fish are capable of acclimating over time to water parameters even extremes. Tetras, angels, discus are troublesome with water quality issues, but most fish jsut need enough time to adjust.... but generalization of the situation doesn't paint a clear picture of the issue and can't lead to a solution to correct it.

Maybe you need to rethink the tank set up and do and over under with the 29g, and blow the 29g out with plantings to use up nitrates to supplement the 50g, a nitrate sump and pass the water through the 29g heavy planted tank to remove nitrates for the 50 gallon lighter planted tank, maybe you keep shrimp and snails in the 29g jungle sump to use up some calcium and the plants to use up potassium and phosphates and keep, it becomes a GH dropper as well as a nitrate remover. heavily planted, lightly stocked with small calcium using critters. and your 50g for your fish, after the plants have worked their magic and nitrates are brought down.
If KH is high, pretty sure you could use and acid buffer to lower KH, and it would produce CO2, which would benefit the plants also, maybe you store water in the 29g heavily planted and lightly stocked tank between water changes, and it does the work of cleaning up the nitrates and lowering GH and KH, and you use 25g of that water for water changes when nitrates are low, and re-top it with high nitrate water again. to lower it before the next water change.

Maybe you need a RO/DI filter and build your water after for the aquariums, but if you do, I have no idea how you manage to keep shrimps currently. if you have 11-12 dGH and dKH, its not a big deal. neither will really affect the fish, unless it's affecting the pH and raising or lowering it depending on what the parameters actually are. barring that it's not a big deal, it's the extreme ends of KH and GH that cause problems.

No way of knowing what the best solution is. without knowing how bad the problem really is. but it really can't be that bad if you are keeping fish and shrimp in it. there is a solution though and I don't think it's really all that extreme of an answer.

So I’ll be honest, I never test my fish tanks. My shrimp tanks are RO water, and I don’t do water changes on them, so I test the GH & KH to see if I need to add anything when I top them off. I have a RO system for drinking water that was here when we bought the house. It’s not practical for use with big tanks.
But you guilted me into testing.
Tap water Nitrates are 20ppm. Not as bad as I thought they’d be.
PH is 7.4
GH is 18
KH is 12
Nitrates in the tank are 0. Excuse me what?! Imagine my surprise. I did a water change Tuesday. I guess my plants are using up the nitrates. If you look at the picture, it is heavily planted. It’s a dirted tank with a dwarf sag carpet and some big swords, a few crypts, some Anubias, floating hornwort, and a $#!? ton of duckweed. I’m pleasantly surprised, lol. I have 9 endlers in my 29g, so I’m thinking I will move them to the 50g. I’m going to break down and redo the 29g. I’ve got the stuff to make it a dirted tank as well, just have to sift the soil. So boring, but necessary.
Thanks again for making me test my tank

 

[Cherryshrimp420]

So I’ll be honest, I never test my fish tanks. My shrimp tanks are RO water, and I don’t do water changes on them, so I test the GH & KH to see if I need to add anything when I top them off. I have a RO system for drinking water that was here when we bought the house. It’s not practical for use with big tanks.
But you guilted me into testing.
PH is 7.4
GH is 18
KH is 12
Nitrates are 0. Excuse me what?! Imagine my surprise. I did a water change Tuesday. I guess my plants are using up the nitrates. If you look at the picture, it is heavily planted. It’s a dirted tank with a dwarf sag carpet and some big swords, a few crypts, some Anubias, floating hornwort, and a $#!? ton of duckweed. I’m pleasantly surprised, lol. I have 9 endlers in my 29g, so I’m thinking I will move them to the 50g. I’m going to break down and redo the 29g. I’ve got the stuff to make it a dirted tank as well, just have to sift the soil. So boring, but necessary.
Thanks again for making me test my tank

Yes that's normal, If you have good plant growth and keep feeding low there should be a decrease in nitrates over time. A healthy planted tank is a nitrate filter, I wouldn't change anything about it