Finding the right tank mates

1L19

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I've chosen three fish for my new 55 gal tank and I'm looking for a fourth tank mate. I've some candidates and I'm looking for any insight folks might have as well the answer to some questions. Thank you!

Tank Parameters
  • No live plants, silk only
  • Mostly wood hardscape and perhaps a few rocks
  • Minimal phosphates by design
  • R/O water
Selected Fish
  • 1x Honey Gourami (might consider a group but concerned about getting the sexing right for a group)
  • 8-10x - Julii Cory (or False)
  • 13x - Neon Tetras
Potential Tankmates
  • Longfin Blue (Leopard, Golden Zebra, Hikari, Zebra) Danio
  • Guppy
  • Rasbora (Harlequin, Glowlight)
  • Molly
  • Platy
  • Other Tetra (Cardinal, Pristella, Diamond, Glowlight, Flame)
Next the questions then the chart. Not saying it's the best reference in the world but I use Animal-World for the fish statistics as it has quite a lot of info.

Questions
  1. The live bearers, Guppies a bit but definitely the Mollies and Platies, call for 1.24 t of salt per gallon added to the tank. I wouldn't mind doing that but should I be concerned about the effect it might have on the tetras, julii corys and the gourami?
  2. I definitely don't want to breed so can I just assume any fry will just get eaten or should I simply avoid the live bearers?
  3. How much should I worry about the parameters in the chart? The obvious issue would be the hardness requirements for the Molly but does it matter that much?
  4. They all seem to be peaceful, have similar activity, require the same light and water movement but is there anything important that I'm not considering? Mistakes are my forte. :)
Parameter Comparison

Purple is the range for that particular fish and green is the area of overlap between all the candidates.

Water parameter comparison.jpg
 

Naughts

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What is the dGH, pH and KH of your source water? The hardness definitely is important for the fish so we need to establish the levels in the water and then choose suitable fish.
 
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1L19

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What is the dGH, pH and KH of your source water? The hardness definitely is important for the fish so we need to establish the levels in the water and then choose suitable fish.

Thank you Naughts for checking out my post. Unfortunately I don't have that information available this time. Neither my test kit nor my RO Filter (AR122 KoolerMax) have arrived yet. I do see, though, that dGH is an important factor so I shall keep that in mind. Very much appreciate you taking your time to help me out. Cheers!
 

ClownLurch

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Welcome to tff.
Once you get your test kit check your preferred fishes requirements on seriouslyfish.com. It’s science backed and not an out and out commercial operation like the site you linked to upthread.
Then check their compatibility with each other on here. There’s some very very knowledgeable and helpful posters on here. Don’t rush into anything.
best of luck.
 

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Thank you Naughts for checking out my post. Unfortunately I don't have that information available this time. Neither my test kit nor my RO Filter (AR122 KoolerMax) have arrived yet. I do see, though, that dGH is an important factor so I shall keep that in mind. Very much appreciate you taking your time to help me out. Cheers!

Check the website of your water authority, it likely has data there and may include GH. The KH (Alkalinity) is also worth knowing. And their pH value (this can change, but GH and KH are less likely to unless targeted. But--this assumes you use the tap water.

You mention in post 1 using RO. If this is the case, then presumably the GH/KH are zero, and the pH around 7 (neutral) unless you mix R/O with some tap.

Phosphates...in R/O these should be zero. Phosphates will occur through fish foods, but hopefully no where else. To your questions.

The live bearers, Guppies a bit but definitely the Mollies and Platies, call for 1.24 t of salt per gallon added to the tank. I wouldn't mind doing that but should I be concerned about the effect it might have on the tetras, julii corys and the gourami?

Salt as meaning common salt, sodium chloride, should never be added to any freshwater fish aquarium on a "regular" basis, only as a medication for specific disease if salt is the best option. This would be temporary, and most freshwater fish can manage with this. Livebearers do not need sodium chloride, they need mineral salts, especially calcium and magnesium (these make up the GH). While mollies can deal with salt (sodium chloride) better than say soft water species, it is certainly not necessary for good health. Salt is detrimental to all freshwater fish to varying degrees. My article on Wet Web Media explains this:

The salt issue leads to your question on parameters.
How much should I worry about the parameters in the chart? The obvious issue would be the hardness requirements for the Molly but does it matter that much?

GH is crucial to fish. The pH is less so but important, depending. The KH is not as directly impacting, but it factors in when considering the pH fluctuations.

The GH ranges in the chart are way off the mark. So much so as I would forget the site completely. GH is the level of dissolved "hard" minerals, primarily calcium and magnesium, and these are crucial for fish well-being. There are fish (freshwater only being discussed) that need these minerals in the water because they cannot get sufficient from food. There are other fish that do not need these minerals and can suffer if they are high. It has to do with evolution of each distinct species in a very individual habitat. The fish for instance that live in the Amazon rainforest have evolved to function in very soft water; livebearers as an opposite example have evolved in water containing these minerals. While nothing is cut and dried, there are limits. All of this is part of the individual genetic blueprint of each species of freshwater fish.

Water is continually entering fish via osmosis through the cells (how fish "drink"). Substances dissolved in the water and that are able to diffuse across the cell membranes (minderals can and do) enter the fish's bloodstream and internal organs. The kidneys filter out "toxins" and in the case of soft water fish with calcium it blocks the kidneys and the fish dies. This may be long-term, and it weakens the fish so the fish may succumb to some other issue and the calcium not really be detected as the actual issue. Hard water fish have the opposite problem, getting the minerals they require.

If you have RO water, or very soft to soft water, you are not going to have healthy mollies, or other livebearers. Guppies are a bit of an anomaly but we'll needn't get bogged down further at this point. The tetras, rasboras, gourami, and most any fish from South America, SE Asia, Central Africa will thrive in this water. By contrast, some of these fish may survive but certainly not thrive in water that is hard.

There are other issues to consider, but the above is significant at this stage. I heartily endorse Seriously Fish as a reference for sound advice.
 
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1L19

1L19

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Welcome to tff.
Once you get your test kit check your preferred fishes requirements on seriouslyfish.com. It’s science backed and not an out and out commercial operation like the site you linked to upthread.
Then check their compatibility with each other on here. There’s some very very knowledgeable and helpful posters on here. Don’t rush into anything.
best of luck.
ClownLurch thank you for the information. I didn't really know the backers of Animal-World but they did have a lot of information so it was a starting point. I'm already checking out Seriously Fish right now and will update my statistics. Compatibility I've already checked but that's from a couple of charts on the net so if SF has one I'll be sure to review it.

Thank you again!
 
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1L19

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Check the website of your water authority, it likely has data there and may include GH. The KH (Alkalinity) is also worth knowing. And their pH value (this can change, but GH and KH are less likely to unless targeted. But--this assumes you use the tap water.

You mention in post 1 using RO. If this is the case, then presumably the GH/KH are zero, and the pH around 7 (neutral) unless you mix R/O with some tap.

Phosphates...in R/O these should be zero. Phosphates will occur through fish foods, but hopefully no where else. To your questions.



Salt as meaning common salt, sodium chloride, should never be added to any freshwater fish aquarium on a "regular" basis, only as a medication for specific disease if salt is the best option. This would be temporary, and most freshwater fish can manage with this. Livebearers do not need sodium chloride, they need mineral salts, especially calcium and magnesium (these make up the GH). While mollies can deal with salt (sodium chloride) better than say soft water species, it is certainly not necessary for good health. Salt is detrimental to all freshwater fish to varying degrees. My article on Wet Web Media explains this:

The salt issue leads to your question on parameters.


GH is crucial to fish. The pH is less so but important, depending. The KH is not as directly impacting, but it factors in when considering the pH fluctuations.

The GH ranges in the chart are way off the mark. So much so as I would forget the site completely. GH is the level of dissolved "hard" minerals, primarily calcium and magnesium, and these are crucial for fish well-being. There are fish (freshwater only being discussed) that need these minerals in the water because they cannot get sufficient from food. There are other fish that do not need these minerals and can suffer if they are high. It has to do with evolution of each distinct species in a very individual habitat. The fish for instance that live in the Amazon rainforest have evolved to function in very soft water; livebearers as an opposite example have evolved in water containing these minerals. While nothing is cut and dried, there are limits. All of this is part of the individual genetic blueprint of each species of freshwater fish.

Water is continually entering fish via osmosis through the cells (how fish "drink"). Substances dissolved in the water and that are able to diffuse across the cell membranes (minderals can and do) enter the fish's bloodstream and internal organs. The kidneys filter out "toxins" and in the case of soft water fish with calcium it blocks the kidneys and the fish dies. This may be long-term, and it weakens the fish so the fish may succumb to some other issue and the calcium not really be detected as the actual issue. Hard water fish have the opposite problem, getting the minerals they require.

If you have RO water, or very soft to soft water, you are not going to have healthy mollies, or other livebearers. Guppies are a bit of an anomaly but we'll needn't get bogged down further at this point. The tetras, rasboras, gourami, and most any fish from South America, SE Asia, Central Africa will thrive in this water. By contrast, some of these fish may survive but certainly not thrive in water that is hard.

There are other issues to consider, but the above is significant at this stage. I heartily endorse Seriously Fish as a reference for sound advice.

I'm making my own RO water with a Filter Direct AR122 6 Stage RO RODI filter and my tap water is the source. I'll be using Rowaphos in my Aquatop canister filter as one goal is to completely eradicate phosphates in my water as much as food/waste will allow.

Thank you very much for the information on salt. I will disregard that information and will instead check out (as ClownLurch also suggested) Seriously Fish. In fact I'm already on there now and reviewing the parameters for my fish of interest. Your information on hardness was eye opening. It makes me call into question all of those fish compatibility charts which put tetras (for example) and live bearers together. Peaceful is peaceful but if they can't share the same water then they aren't really "compatible"... it seems.

You took out a lot of your time to help me out and I truly appreciate it. So many forums when you post your only reply is *cricket chirp*. When my tank is up and running I will attribute any success to yourself and the others who have been so kind with their time.
 

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If you are willing to read related articles, I have one on GH and pH posted on the blog of one of our members, here's the link:

and on related TDS

This is a complex subject, and I tried earlier to pare it down to the basic principle. There are fish that will only survive in very soft water. There are also fish that occur in such water but can manage in somewhat harder water. There are fish that will only survive healthily in hardish water. This is where we get into fish surviving or managing as opposed to actually thriving. The gourami for instance is a soft water species, but it will do well (as far as anyone can tell--none of us can talk to the fish to ask it) in somewhat harder water. So there is overlap, but (a) how far does this go with species "x", and (b) is it really "OK" to the fish, or not? Subject to the actual GH, Pristella tetras could easily live with livebearers. But this would not be the case with say green neon tetras and mollies.
 
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1L19

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This is neither here nor there but I just took a look at the Neon Tetra page on Seriously Fish and compared it to the Neon Tetra page on Animal-World and going forward I'll have to use both. I have no doubt, based on the comments, that the numbers are more accurate on Seriously Fish but Animal-World has some additional information not found on Seriously Fish (at least I didn't see it). Suitable substrate (not best for display), how much water movement preferred, tank position in which a fish might swim, more details on food/feeding, details on how difficult a fish is to keep with a rating, water change frequency, more details on social behavior, etc.

It doesn't escape me that if the numbers on animal-world are off then the rest of their information might be suspect. That said it's better to have something than nothing... at least for the clueless like me. :)
 

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This is neither here nor there but I just took a look at the Neon Tetra page on Seriously Fish and compared it to the Neon Tetra page on Animal-World and going forward I'll have to use both. I have no doubt, based on the comments, that the numbers are more accurate on Seriously Fish but Animal-World has some additional information not found on Seriously Fish (at least I didn't see it). Suitable substrate (not best for display), how much water movement preferred, tank position in which a fish might swim, more details on food/feeding, details on how difficult a fish is to keep with a rating, water change frequency, more details on social behavior, etc.

It doesn't escape me that if the numbers on animal-world are off then the rest of their information might be suspect. That said it's better to have something than nothing... at least for the clueless like me. :)

Aside from the charts, I have no direct experience with Animal World, so I will try to take a look at it. I would just say though that some of the "data" like foods, substrate colour [this is of more importance than one might think], water flow, social behaviour are usually included in the profile on SF, under relative sections.

And there is always this forum, there are many knowledgeable members here and when one of us posts we have peer review which means we are not going to get away with posting rubbish. :fish:
 
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If you are willing to read related articles, I have one on GH and pH posted on the blog of one of our members, here's the link:

and on related TDS
Ok so I read both articles (you didn't think I was going to... did you? :) ) and I have a question.

TDS is basically everything dissolved in the water: chlorine, chloramine, ammonia, phosphate, salt, hard minerals (GH), bicarbonates (KH), etc. And almost every substance added to the water will increase TDS: water conditioner, fish foods, plant fertilizers, calcareous substances, medications, water adjustment products, etc.

The Effect of TSS and TDS in the Aquarium and on Fish

As the above definition indicates, filtration via aquarium filters will (or should) remove the TSS but will not remove any TDS from the water [see later on carbon]. While live plants can use some of them, only a partial water change effectively removes the TDS that naturally increase within the aquarium.

If TDS is everything in the water and a filter removes some (TSS) why wouldn't that affect the TDS?

I learned a lot. Thank you very much. :)
 

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If TDS is everything in the water and a filter removes some (TSS) why wouldn't that affect the TDS?

This is taxing my brain...I wrote this in 2012 and long before cancer appeared which is making me think longer about things. But I think I refer to this early in the article...

TDS) is a measure of the combined content of all organic and inorganic substances contained in the water in molecular, ionized or micro-granular (colloidal sol) suspended form. Generally the operational definition is that the solids must be small enough to survive filtration through a sieve the size of two micrometer.​
I don't believe our filters can catch these. Fish pheromones and allomones for example are dissolved in the water...these cannot be removed by filter media. If such substances are able to diffuse across cell membranes, I cannot see them getting trapped in a filter. But I wouldn't debate this if someone has something.
 
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This is taxing my brain...I wrote this in 2012 and long before cancer appeared which is making me think longer about things. But I think I refer to this early in the article...

TDS) is a measure of the combined content of all organic and inorganic substances contained in the water in molecular, ionized or micro-granular (colloidal sol) suspended form. Generally the operational definition is that the solids must be small enough to survive filtration through a sieve the size of two micrometer.​
I don't believe our filters can catch these. Fish pheromones and allomones for example are dissolved in the water...these cannot be removed by filter media. If such substances are able to diffuse across cell membranes, I cannot see them getting trapped in a filter. But I wouldn't debate this if someone has something.
You'll get no debate from my sir as I don't know how any of this works. You taught me more about the subject in 15 minutes than I'd gathered up to this point in my life. I understand what you mean now. I think you are basically saying C is A + B but just because you reduce B it won't reduce A. Anyway I was just trying to check my understand and thank you for the information in a compact package. :)
 

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You'll get no debate from my sir as I don't know how any of this works. You taught me more about the subject in 15 minutes than I'd gathered up to this point in my life. I understand what you mean now. I think you are basically saying C is A + B but just because you reduce B it won't reduce A. Anyway I was just trying to check my understand and thank you for the information in a compact package. :)
Stick around mate. You sound like one of the good guys. I returned to fishkeeping after 23 yrs a couple of years back and the science had moved on. Thankfully.
 
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Just an update but I went back and redid the numbers based on Seriously Fish and my chart definitely looks different. I really think the mollys are out due to their hardness needs. I think I could pull off the platys or the guppies but I'd probably have to add some tap water back to my RO water to raise the hardness. Honestly though I don't want to deal with that on a regular basis so currently it seems like the best mates are either the danios or the rasboras. Thanks all!


Water parameter comparison 2.jpg
 

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