Freshwater Fish for 40 gallon tank

[Essjay]

In an area where there are periods of heavy rainfall interspersed with periods of little rainfall, that could cause changes in hardness - the heavy rain would be like mixing tap water with RO.
Some water providers switch water sources and depending on what the before and after hardness is like, it could be a significant change in hardness.
The only way we can know is to periodically check the GH of our tap water.

To be honest, I don't know how we should cope when water changes a lot throughout the year beyond keeping fish with a large hardness range. Or keeping fish which need the soft end of the water provider's range and use RO for water changes if the water becomes too hard.

 

[mcordelia]

ok thanks! I guess if nothing else it'll be a learning experience for me and I can write about it

Pardon the interruption, back to OP's topic of choosing fish for their specific situation

 

[FishLover166]

But can I keep these fish together in this sized tank-
-4 guppies
-10 dwarf neon rainbows
-4 pearl gourami, 1 male, 3 female
-4 dwarf petricola
-6 or more neon tetras
-5 panda corys
I want the fish to be comfortable, and not fight. I just researched all the pH and dKH levels of the different fish. I can also upgrade my plan; no more then 50 gallons, though.

 

[Essjay]

dKH levels

You need GH not KH. KH (carbonate hardness) only affects fish indirectly by stabilising pH.


No you can't keep all those fish together. You need to find out the GH of your water and cross off the list those species which wouldn't be happy in that GH.

If you have soft water, 4 pearl gouramis, panda cories (6 or more) and neon tetras would be OK together. You could increase the numbers of cories and tetras, and perhaps have another soft water species.

If you have hard water, the dwarf petricolas would be fine, and depending how hard, the dwarf rainbows could be OK. Guppies might not as they are small fish which could be eaten by the petricolas. If you leave out the petricolas, guppies, platies, dwarf rainbows (if it's no too hard) would be OK together. Maybe some of the Psedomugil species as well.

 

[FishLover166]

I just found out my water is hard, because my step-mother got a water test because she wanted to know exactly what was in the water. Our water is VERY hard.

 

[mcordelia]

Rainbows are beautiful and do well in hard water, also swordtails, mollies and platys. I started a thread earlier today about which tetras do well in hard water, you should look that up. There are certain species of cories that can be ok in harder water, depending on HOW hard it is, there is a thread on the forums that lists those species as well.

I would STRONGLY ENCOURAGE you to take a sample of your water to your local pet store and get it tested for hardness, since your particular well may or may not fall into the "most well water" category.

 

[FishLover166]

Ok, I will if I can. Thanks.

 

[FishLover166]

I am 150% sure that the water is hard. It is actually it is on the very hard side of hard, so would the fish be fine in VERY hard water?

 

[Colin_T]

While everyone is talking about GH, KH and pH, you should also check the well water for ammonia, nitrite, nitrate and phosphate, and anything else you can test. Sometimes nutrients get into ground water and can contaminate the well water so you need to check it regularly for everything you can, not just the hardness. If you have nutrients in the well water you can poison the fish and yourself.

 

[mcordelia]

Great points @Colin_T . I assumed that since it's actively in use, ammonia etc probably shouldn't be present in meaningful amounts, but spaceships have been lost due to assumptions....

 

[Colin_T]

It doesn't matter how actively the well is used, ground water can become contaminated at any time. It might be perfect one day and toxic the next. Having said that, it should be reasonably safe but should be checked once a month or so.