Are some fish okay with a higher pH if the hardness is correct for them?

[rebe]

Hi all,
Tomorrow I'll be going to the LFS in the city closest to me. I have the names of the fish I want to consider, and I've been jotting down each fish's requirements to bring with me. Some of the fish I'd like to have or at least consider have water requirements a bit different than mine. For example, the black skirt tetra on seriously fish has a pH of up to 7.0 but my tank/tap water is 7.6. But the hardness of my water is only 9 (german degrees) which is within the 5-20 range of the tetras.
I've heard/seen people say that the water hardness is more important than the pH, so would I be able to get fish like the tetras with my water?

 

[seangee]

They will be fine.

 

[Ichthys]

Yes, they’ll be ok.

 

[GaryE]

Just to throw an idea out - I used to breed wild caught Apistogramma njisseni, from a pH of about 5.0 with no measurable hardness. They would breed, produce equal ratios among their young and live their lifespan in water at a pH of 6.6 to 6.8. But if I let the hardness drift above 50ppm, nada. They lived, but they didn't get beyond the purchased generation.
I think we go a little pH crazy in the hobby because it's an easy reading to take, and we had those test kits before the hardness ones were easily available. pH can matter, but not for most Amazon fish, as long as the water's soft.

Black skirts? For the sake of all that is holy and good looking, there are dozens of way nicer tetras out there. Black skirt/white skirt/black widow/widow/glo-tetras (they have more trade names than charms) can be nippy, and grow large and slow. There are so many nicer options, in my prejudiced opinion.

 

[Ichthys]

Black skirts? For the sake of all that is holy and good looking, there are dozens of way nicer tetras out there. Black skirt/white skirt/black widow/widow/glo-tetras (they have more trade names than charms) can be nippy, and grow large and slow. There are so many nicer options, in my prejudiced opinion.

I don’t normally diss a fish, but I have to agree. Just so you know, @rebe (if you don’t already), black skirts look lovely when they’re small and black, but they grow up to be pale grey and lazy/boring. Apologies black skirts.

 

[TwoTankAmin]

Unless one is keeping fish that require sespecially acid or alkaline water- think Altum angels in 4.0 or some rift lakes cichlids at 8.5+. pH is not as big a deal as we often read. TDS (conductivity) is way more important. I can tell you that I have dropped the pH in my Altum tank by 1.0 in about 5 minutes by adding muriatic acid to the water. The fish did not even notice. What the do need is having very soft water.

Fish need to have a balance between their internal systems and the external water parameters when it comes to TDS. Here is a quick explanation which highlights the difference between fresh and salt water fish:

Osmoregulation in Fish​

Freshwater fish and marine fish osmoregulate in different ways. The environments which they have varying levels of salinity, hence the process of osmoregulation is different.​

• Osmoregulation in Freshwater Fish

Freshwater fishes are hypertonic to their surrounding environment, which means that the concentration of salt is higher in their blood than their surrounding water. They absorb a controlled amount of water through the mouth and the gill membranes. Due to this intake of water, they produce large quantities of urine through which a lot of salt is lost. The salt is replaced with the help of mitochondria-rich cells in the gills. These cells absorb salt into the blood from the surrounding water.

• Osmoregulation in Marine Fish

Compared to freshwater fish, marine fish face the opposite problem. They have a higher concentration of water in their blood than their surrounding environment. Consequently, it results in the tendency to lose water and absorb the salt. To get around this problem, marine fish drink large quantities of water and restrict urination. Another additional energy expenditure also arises as these organisms actively need to expel salt from the body (through the gills).

from https://byjus.com/biology/osmoregulation/

This is why TDS/conductivity matters more than pH in most cases.

 

[rebe]

I don’t normally diss a fish, but I have to agree.
...but they grow up to be pale grey and lazy/boring.

Black skirts? For the sake of all that is holy and good looking, there are dozens of way nicer tetras out there.

My first comment is that I found these comments very funny and amusing! I didn't realise that they lost their colour as they aged. I was not set on black skirts thankfully. An example of a fish in the LFS with the PH "problem".


I'd be very interested to know which you would pick from these, and if there are any red flags:

• Kerri emperor tetra
• "Whitefin Tetra" (possibly they meant hyphessobrycon bentosi ?)
• "Rosy Tetra" (probably hyphessobrycon rosaceus)
• Congo Tetra
• Glass Bloodfin Tetra
• Chequer Barbs
• Rhombo Barbs

Those are the fish I saw in the LFS, but there may have been a few species I missed. If there aren't any good ones or enough in the LFS tomorrow, I can order fish online from https://www.masterfisch.eu/en/
Though it will work out better for me to get them in person tomorrow when I have a day off instead of during the week when I'm at college.

 

[rebe]

Unless one is keeping fish that require sespecially acid or alkaline water- think Altum angels in 4.0 or some rift lakes cichlids at 8.5+. pH is not as big a deal as we often read. TDS (conductivity) is way more important.

This is why TDS/conductivity matters more than pH in most cases.

Just to check, is TDS measured in GH/KH test kits? If not, I don't know what mine is.
Really good bit of reading, thank you!

 

[Essjay]

TDS includes GH and KH but it contains more than just them. TDS (total dissolved solids) is measured with a meter rather than a tester like GH etc.

 

[WhistlingBadger]

I got some rosy tetras on a whim a few months ago and they've become one of my favorite fish. Active, friendly, and they color up really nicely. I can't remember how big your tank is, Rebe, but they're also small enough that you can get a nice, big school if your tank is reasonably sized. If you can find some, get them!

 

[TwoTankAmin]

Actually, a TDS pen or monitor actually is measuring the conductivity. it then applies a formula to the conductivity which results in the ppm we get for TDS. My more complex 3-way monitor can read conductivity or else it can apply one of two formulas to get two different ppm reading for TDS.

I find I can more easily understand the ppms of TDS than the microsiemens of conductivity. (And no, they are not tiny sailors.)

 

[rebe]

@WhistlingBadger My tank is 120x60x40cm (280L) so if the LFS has a reasonable number in stock, then I think they will be one of my top choices! A few people I know have really good experiences with them, so I'll probably get them unless I find something I really want to have

I assume it's not the best idea to only get a small group then buy more somewhere else at a later time? (Due to LFS stock or lack of.)
It's sad to see the "leftover" fish in the tanks. Last week there was a tank with three diamond tetras and one poor little hatchet fish :')

 

[WhistlingBadger]

@WhistlingBadger My tank is 120x60x40cm (280L) so if the LFS has a reasonable number in stock, then I think they will be one of my top choices! A few people I know have really good experiences with them, so I'll probably get them unless I find something I really want to have

I assume it's not the best idea to only get a small group then buy more somewhere else at a later time? (Due to LFS stock or lack of.)
It's sad to see the "leftover" fish in the tanks. Last week there was a tank with three diamond tetras and one poor little hatchet fish :')

Yeah, all hatchets and tetras seem to like large groups. My rosies always hang out together.

 

[Byron]

My first comment is that I found these comments very funny and amusing! I didn't realise that they lost their colour as they aged. I was not set on black skirts thankfully. An example of a fish in the LFS with the PH "problem".


I'd be very interested to know which you would pick from these, and if there are any red flags:

• Kerri emperor tetra
• "Whitefin Tetra" (possibly they meant hyphessobrycon bentosi ?)
• "Rosy Tetra" (probably hyphessobrycon rosaceus)
• Congo Tetra
• Glass Bloodfin Tetra
• Chequer Barbs
• Rhombo Barbs

Those are the fish I saw in the LFS, but there may have been a few species I missed. If there aren't any good ones or enough in the LFS tomorrow, I can order fish online from https://www.masterfisch.eu/en/
Though it will work out better for me to get them in person tomorrow when I have a day off instead of during the week when I'm at college.

There are other issues here. First, the species in the genus Aphyocharax (the "bloodfins") are notorious for fin nipping. And unbelievably so.

Barbs depends, they are generally more robust and active, which does not settle them well with less active fish. The Congo Tetra might have problems heree, and the tetras (whichever species).

King Emperor, not sure of the species but these are more robust that many others. I had them once and they had to be removed (gave them to someone who was clearly told of their antics, so...).

 

[rebe]

Congo Tetra might have problems here

Problems with the water? Or did you mean with the tank and/or tank mates?
When you say "and the tetras", is that about whichever problem would apply to the congos too?
Thank you