240g stocking/compatibility help

duanes

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One thing to consider,
whether you feed fish or not, freshwater fish are constantly urinating (mostly thru the gill). And that urine is more of a concern that other detritus.
With large fish, unless you your change some water and dilute the urine (no matter what size tank) your pH will fall due to uric acid. Plants will use some, the filter bacteria will use some, but unless your plants outweigh your fish, you will need to do regular water changes, unless your stocking level is very low (which from your list, is not).
If your tap water has a high buffering capacity, then fewer than if it has a low buffering capacity.
 

duanes

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Staff member
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Jun 7, 2007
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27,306
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Isla Taboga Panama via Milwaukee
One thing to consider,
whether you feed fish or not, freshwater fish are constantly urinating (mostly thru the gill). And that urine is more of a concern that other detritus.
With large fish, unless you your change some water and dilute the urine (no matter what size tank) your pH will fall due to uric acid. Plants will use some, the filter bacteria will use some, but unless your plants outweigh your fish, you will need to do regular water changes, unless your stocking level is very low (which from your list, is not).
If your tap water has a high buffering capacity, then fewer than if it has a low buffering capacity.
 
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robham777

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Basically, in all my tanks I try to stock at a level where nitrates are kept at a safe level without the help of a sump even though I intend to have one in this setup. Which is why I like planted tanks so much. I like to play it safe since life happens and who wants to deal with water changes every couple of days anyways? I’m not familiar with fish this large which is why I wanted some insight on where I stood concerning bioload.
I try and do the same. I have over a dozen tanks and like to have some wiggle room on water changes. For the large fish like the oscar,bgk, and ornate at full size I would allocate around 75 gallons and maybe the same for the sd school to keep it at once per week 50% water changes(doing more is of course better). Just a ballpark since plants, feeding, tap water and other factors will come in to play. Unless you purchase the fish adult size you should have a long while before bioload is a real factor in your proposed system.
 
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JohnnyHyde

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BenPen, as I wrote before - not fish produce waste, but you do. It's same with humans and all the animals - if you won't feed them, they won't produce waste. When you feed them - part of the food goes to growth, reproduction, energy and remaining comes as waste (in case there're any leftovers, then leftovers = pollution).

As plant eating fish - I doubt that you'll be able to tell them - eat this plant and not the other... :))

Fast growing plants lower the no3, so the water changes generally. Good filtration can also help a little with no3 in case of anoxic environment. But I doubt that you'll be able to do that with sump. Also, I don't see a point in using all the other filters in your situation. What do you try to achieve? more surface? Bacteria grows on all surfaces - inside your aquarium as well and the largest surface is your gravel/soil. The sump will be enough for bio and mech. Having a "prefilter" sponge on your inlet pipe would help for the sump to keep larger particles outside of it and serve as a mech. filtration too.

Carpeting plants. I can't talk about the "hard ones" like Hemianthus callitrichoides, which probably require co2 in order to survive..., however I never used co2 (the reason behind that - I don't want to trim it often and the usual issues with algae comes much faster... basically all the problems in tank needs much quicker reaction). Just do a dry start and plants like monte carlo will be ok (just not ok with large bichir…)

Rainbowfish will probably become food for larger fishes, but if you have other tanks or If you get them fully grown, they would be good for quite some time. When you see them starting to disappear - rehome to other tank or just let the nature take its course. (I've seen amano shrimp living with Erpetoichthys calabaricus and red cherry with male betta. Both somehow survive to this day (6-10 months) - after that, all I can say - It really comes to character of the fish)

I'm far from expert, but I don't see a point in thinking "will my fish be ok when fully grown...". Unless you can get them already grown up, you'll face many difficulties along the road to fish maturity (like your oscar story...) which might naturally show that only the "strongest" (or luckiest) will survive. About the water changes - I also can contradict the opinion on weekly water changes. I always wondered about those with their "I always do weekly 50-75% water changes" and their vocation? Or their family goes on vocation and they stay home to do their water changes? Just get many tests and test water every 2-5 days... When stocking your aquarium - same. Introduce the fishes one/few at a time and check the readings. Wait for few weeks when constantly checking parameters. Bacteria will adapt to increased, your provided, food load. The only reason behind weekly water changes is that new water introduce elements needed for plants (and probably fishes), but there won't be a difference if you do it daily or weekly or almost monthly. Check parameters and if needed - change water.
 
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robham777

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BenPen, as I wrote before - not fish produce waste, but you do. It's same with humans and all the animals - if you won't feed them, they won't produce waste. When you feed them - part of the food goes to growth, reproduction, energy and remaining comes as waste (in case there're any leftovers, then leftovers = pollution).
Not true, if a fish is fed at all it will produce ammonia. The process of converting the protein in food for energy (catabolism) is where the majority of the the nitrogenous waste produced by fish comes from. The solid waste and uneaten food factors in because the bacteria that are breaking it down produce ammonia in the process. If a fish is living it is producing some level of ammonia, and the larger the fish the higher the amount will be. The end result is nitrate in a cycled aquarium and study after study have shown that maintaining low levels is beneficial to fish. Plants can play a role in reducing nitrate, but are not nearly as effective as water changes.

As far as water changes go, the optimal nitrate level is zero so even if at 1 week you have only 10 ppm accumulation it is still beneficial to reduce it. If you want to set a level that is acceptable and test until that concentration is reached then that is up to you.
 
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Gourami Swami

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BenPen, as I wrote before - not fish produce waste, but you do. It's same with humans and all the animals - if you won't feed them, they won't produce waste. When you feed them - part of the food goes to growth, reproduction, energy and remaining comes as waste (in case there're any leftovers, then leftovers = pollution).

I'm far from expert, but I don't see a point in thinking "will my fish be ok when fully grown...". Unless you can get them already grown up, you'll face many difficulties along the road to fish maturity (like your oscar story...) which might naturally show that only the "strongest" (or luckiest) will survive. About the water changes - I also can contradict the opinion on weekly water changes. I always wondered about those with their "I always do weekly 50-75% water changes" and their vocation? Or their family goes on vocation and they stay home to do their water changes? Just get many tests and test water every 2-5 days... When stocking your aquarium - same. Introduce the fishes one/few at a time and check the readings. Wait for few weeks when constantly checking parameters. Bacteria will adapt to increased, your provided, food load. The only reason behind weekly water changes is that new water introduce elements needed for plants (and probably fishes), but there won't be a difference if you do it daily or weekly or almost monthly. Check parameters and if needed - change water.
Not quite sure what you are trying to say here. Fish won't produce waste unless you feed them? Ok, but you have to feed them or they will starve. True that feeding a bit lighter can help keep nitrates down, but you don't want to be starving your fish just to prolong your next water change.

And the point in thinking "will my fish be ok when fully grown" is that if you take good care of your fish, they will be fully grown shortly. Oscars will be 10"+ within the first year they are born, if kept in clean water. Why would you recommend somebody not to plan for the fish to be an adult in such a short time? I am not sure if you have experience keeping fish this size, but as adults, this stocking level will require at least weekly water changes to keep both testable and unseen chemicals in the water at comfortable levels.
 

BenPen

Feeder Fish
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Jul 5, 2018
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Not quite sure what you are trying to say here. Fish won't produce waste unless you feed them? Ok, but you have to feed them or they will starve. True that feeding a bit lighter can help keep nitrates down, but you don't want to be starving your fish just to prolong your next water change.

And the point in thinking "will my fish be ok when fully grown" is that if you take good care of your fish, they will be fully grown shortly. Oscars will be 10"+ within the first year they are born, if kept in clean water. Why would you recommend somebody not to plan for the fish to be an adult in such a short time? I am not sure if you have experience keeping fish this size, but as adults, this stocking level will require at least weekly water changes to keep both testable and unseen chemicals in the water at comfortable levels.
Agreed 1000%. I could certainly understand being conservative when feeding to avoid excess mess and the health risks that come with overfeeding, but the idea of withholding food in an attempt to skip a water change seems kinda lazy to me. No offense meant to anyone, but I guess that's just not my style. No-one likes doing tons of water changes, but that's why I'm putting so much thought into my stocking levels so I'm not spending more time running around with a bucket than I am actually looking at the fish.
I would also never buy a fish without knowing that I can care for it for it's entire life, barring an accident like I had with my Oscar. I certainly wouldn't have purchased him and thrown him in a 10g thinking "well he'll probably end up on my floor and eaten by my dog anyways so why bother with a bigger tank?" When I plan a tank I plan for long term care and compatibility which is why I made this post in the first place.
 

BenPen

Feeder Fish
MFK Member
Jul 5, 2018
42
5
8
MA, USA
Not true, if a fish is fed at all it will produce ammonia. The process of converting the protein in food for energy (catabolism) is where the majority of the the nitrogenous waste produced by fish comes from. The solid waste and uneaten food factors in because the bacteria that are breaking it down produce ammonia in the process. If a fish is living it is producing some level of ammonia, and the larger the fish the higher the amount will be. The end result is nitrate in a cycled aquarium and study after study have shown that maintaining low levels is beneficial to fish. Plants can play a role in reducing nitrate, but are not nearly as effective as water changes.

As far as water changes go, the optimal nitrate level is zero so even if at 1 week you have only 10 ppm accumulation it is still beneficial to reduce it. If you want to set a level that is acceptable and test until that concentration is reached then that is up to you.
I tend to aim for =/<20ppm in a planted tank to avoid starving the plants. I know some aquarium critters are more sensitive to nitrates than others, any idea if my intended stock is part of that percentage?
 

BenPen

Feeder Fish
MFK Member
Jul 5, 2018
42
5
8
MA, USA
BenPen, as I wrote before - not fish produce waste, but you do. It's same with humans and all the animals - if you won't feed them, they won't produce waste. When you feed them - part of the food goes to growth, reproduction, energy and remaining comes as waste (in case there're any leftovers, then leftovers = pollution).

As plant eating fish - I doubt that you'll be able to tell them - eat this plant and not the other... :))

Fast growing plants lower the no3, so the water changes generally. Good filtration can also help a little with no3 in case of anoxic environment. But I doubt that you'll be able to do that with sump. Also, I don't see a point in using all the other filters in your situation. What do you try to achieve? more surface? Bacteria grows on all surfaces - inside your aquarium as well and the largest surface is your gravel/soil. The sump will be enough for bio and mech. Having a "prefilter" sponge on your inlet pipe would help for the sump to keep larger particles outside of it and serve as a mech. filtration too.

Carpeting plants. I can't talk about the "hard ones" like Hemianthus callitrichoides, which probably require co2 in order to survive..., however I never used co2 (the reason behind that - I don't want to trim it often and the usual issues with algae comes much faster... basically all the problems in tank needs much quicker reaction). Just do a dry start and plants like monte carlo will be ok (just not ok with large bichir…)

Rainbowfish will probably become food for larger fishes, but if you have other tanks or If you get them fully grown, they would be good for quite some time. When you see them starting to disappear - rehome to other tank or just let the nature take its course. (I've seen amano shrimp living with Erpetoichthys calabaricus and red cherry with male betta. Both somehow survive to this day (6-10 months) - after that, all I can say - It really comes to character of the fish)

I'm far from expert, but I don't see a point in thinking "will my fish be ok when fully grown...". Unless you can get them already grown up, you'll face many difficulties along the road to fish maturity (like your oscar story...) which might naturally show that only the "strongest" (or luckiest) will survive. About the water changes - I also can contradict the opinion on weekly water changes. I always wondered about those with their "I always do weekly 50-75% water changes" and their vocation? Or their family goes on vocation and they stay home to do their water changes? Just get many tests and test water every 2-5 days... When stocking your aquarium - same. Introduce the fishes one/few at a time and check the readings. Wait for few weeks when constantly checking parameters. Bacteria will adapt to increased, your provided, food load. The only reason behind weekly water changes is that new water introduce elements needed for plants (and probably fishes), but there won't be a difference if you do it daily or weekly or almost monthly. Check parameters and if needed - change water.
I'm curious as to your feeding schedules. I typically feed my tanks small amounts twice a day, skipping a meal or full day's feeding a day a week. Is this not recommended for larger fish/cichlids?
Ha, can't blame me for trying! :D It's a good thing I like pothos and have a LOT of it 'cause it sounds like I may be stuck with it. Although I may end up passing on the SDs to ease up on bioload and increase my likelyhood of successfully keeping plants in this thing. I actually have a colony of red cherry shrimp in my betta tank and was thinking of tossing the culls into the 240 for food and how it would be cool if they managed to take off in there too. Maybe I'll attempt something crazy with a small schooler too and see what happens. I'll just keep telling the oscar and bichir that "Fish are friends, not food" and if that doesn't work, they had a dang good meal and I toss the rest in the 40gb. Not sure I'd be willing to risk it with something as pricey as rainbow fish though. Hmmm....
Definitely agree on the last point, my 29g betta tank is so heavily planted that water changes are about a 1-2 times a month thing and usually it's just out of paranoia! Old habits die hard as they say.
 

BenPen

Feeder Fish
MFK Member
Jul 5, 2018
42
5
8
MA, USA
I try and do the same. I have over a dozen tanks and like to have some wiggle room on water changes. For the large fish like the oscar,bgk, and ornate at full size I would allocate around 75 gallons and maybe the same for the sd school to keep it at once per week 50% water changes(doing more is of course better). Just a ballpark since plants, feeding, tap water and other factors will come in to play. Unless you purchase the fish adult size you should have a long while before bioload is a real factor in your proposed system.
That's a good point. I'll probably scratch the SD idea to save on the bioload I'll be dealing with as adults. Thanks for the tips!
 
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