40 gallon / 155liters - silent cycle - green or red? Stocking suggestions please!

[Byron]

I've read the article before and I thought it's really more intended to convince the "no water change" camp to do water changes - I understand the benefits but I'm not sure on what "the more the better" translates into actionable water change volume and frequency of changes. I know all aquariums are different, but I think some examples would go a long way.

20% was the wrong percentage for me to mention, I probably have 120L of water because I need to take into account the substrate and the stones + wood. I was doing 30L water change, that's about 25% and I've just did a maintenance and changed about 48L, so about 40%. I'm happy to do better, but I need clear guidance.

Thanks a lot!

I will have to check and possibly revise my article, as I thought the volume issue was discussed. In the interim, I can respond here.

As fish live in the tank of water, they significantly impact the water through their life processes. No aquarium can ever be even close to natural waters so we need to do things to counter the negatives. The tank water is continually being polluted by all sorts of things, from the obvious like fish waste and respiration, to less obvious like pheromones and allomones, none of which can be removed by any filter, only water changes and plants but the plants take time and most of us have way more fish in a tank for the plants to be successful on their own. I'll use arbitrary numbers to illustrate.

If fish are producing say 100 parts of pollution, changing 70% once a week removes 70 leaving 30. Changing 10% daily removes 10 leaving 90 on day one, then next day (water change) 10 leaving 90--but this is no where near even the first day's 10/90. The pollution is actually accumulating faster than it is being removed. Whereas the effect of the larger volume is to get rid of the majority of the pollution in one go, so the tank will have significantly less pollution going forward.

 

[Unknownfuture]

I will have to check and possibly revise my article, as I thought the volume issue was discussed. In the interim, I can respond here.

As fish live in the tank of water, they significantly impact the water through their life processes. No aquarium can ever be even close to natural waters so we need to do things to counter the negatives. The tank water is continually being polluted by all sorts of things, from the obvious like fish waste and respiration, to less obvious like pheromones and allomones, none of which can be removed by any filter, only water changes and plants but the plants take time and most of us have way more fish in a tank for the plants to be successful on their own. I'll use arbitrary numbers to illustrate.

If fish are producing say 100 parts of pollution, changing 70% once a week removes 70 leaving 30. Changing 10% daily removes 10 leaving 90 on day one, then next day (water change) 10 leaving 90--but this is no where near even the first day's 10/90. The pollution is actually accumulating faster than it is being removed. Whereas the effect of the larger volume is to get rid of the majority of the pollution in one go, so the tank will have significantly less pollution going forward.

This leads me to change 80% of the water per week. As long as your filter is well established these large changes are fine and the difference i've seen in the fish tells me it's a good thing. If you keep it consistent the fish get used to the routine.

 

[Cmdr_DASh]

Thanks for the additional info @Byron, I understand the principle (and math). How much water do you change in your aquarium?

@Unknownfuture appreciate you sharing your routine... my bio load is pretty low in a heavy planted tank, but I'll eventually have more fish in there, so it would make sense to increase how much water I change... I may not hit 80% but knowing that's possible with good consequences is quite good. Thank you!

 

[Byron]

Thanks for the additional info @Byron, I understand the principle (and math). How much water do you change in your aquarium?

@Unknownfuture appreciate you sharing your routine... my bio load is pretty low in a heavy planted tank, but I'll eventually have more fish in there, so it would make sense to increase how much water I change... I may not hit 80% but knowing that's possible with good consequences is quite good. Thank you!

I'm lucky to have tap water with identical parameters to tank water, meaning zero GH and KH. The pH naturally falls low, but it stabilizes within each tank and remains there, and has for years. All my fish are soft/very soft water species so this causes no issues. This situation allows me to change 60-80% once a week; I get working on plant thinning or something, and before I know it, the Python has drained the tank down to these levels.

 

[itiwhetu]

It is interesting I keep seeing the mention of fish waste being a major concern. I have even seen written here that fish are swimming around in their poo. I think this is an exaggeration. If you have a 100 liter tank and you have 30 neon tetras in it. Just for arguments sake each fish weights 5 grams you will then have 150 grams worth of fish and if they manage to poo 10% of their body weight you will have about 15 grams of poo a day, going into 100 liters of water. Not a lot really!
Even if they were in their poo, you would be able to see it as an Ammonia reading which never happens in a normal tank.

 

[Naughts]

Don't forget fish urinate a lot - a third of their body weight a day - so add in 50g per day of urine. It is not just ammonia - urea, amino acids, creatinine and creatine as well as minerals are expelled.

And poo is, well, "organic". The filter should trap TDS but cleaning removes it.

The reason you don't see ammonia on tests is because it is processed by beneficial bacteria in cycled tanks. This process will be inhibited if water changes are not done. The microbes that break down fish waste can out-compete the beneficial bacteria.

A major issue with insufficient maintenance is lack of oxygen, breaking down poo uses far more oxygen than any fish. A decrease in dissolved oxygen and an increase in dissolved wastes, accelerates fish gill clogging and increases mucus production by the fish in an attempt to protect their delicate gill membranes, thus creating an environment for disease.

Excess waste encourages more aggressive heterotrophic bacteria at the expense of the ammonia oxidising bacteria (AOB) and water quality is reduced. The fine balance is hard to achieve without frequent (weekly) large (50%+) water changes.

 

[itiwhetu]

Don't forget fish urinate a lot - a third of their body weight a day - so add in 50g per day of urine. It is not just ammonia - urea, amino acids, creatinine and creatine as well as minerals are expelled.

And poo is, well, "organic". The filter should trap TDS but cleaning removes it.

The reason you don't see ammonia on tests is because it is processed by beneficial bacteria in cycled tanks. This process will be inhibited if water changes are not done. The microbes that break down fish waste can out-compete the beneficial bacteria.

A major issue with insufficient maintenance is lack of oxygen, breaking down poo uses far more oxygen than any fish. A decrease in dissolved oxygen and an increase in dissolved wastes, accelerates fish gill clogging and increases mucus production by the fish in an attempt to protect their delicate gill membranes, thus creating an environment for disease.

Excess waste encourages more aggressive heterotrophic bacteria at the expense of the ammonia oxidising bacteria (AOB) and water quality is reduced. The fine balance is hard to achieve without frequent (weekly) large (50%+) water changes.

I have done simply fine on my 25% water change schedule. The bonus is I have nice acid tanks that the plants and fish love. I never have to think about Ammonia and never have to worry about fertilizers.

 

[Cmdr_DASh]

Today I have:
- 12 cardinal tetras
- around 9 red cherry shrimp
- a handful of snails


I continue to research on fish that would be good additions and I've checked out several LFS. I continue to like dwarf gourami but one LFS told me that 50cm height is too much for dwarf gourami and their lungs can't take that depth - my actual water depth from substrate to surface doesn't exceed 40 cm, sounds like I should be fine. I still don't think I have a good source for dwarf gouramis... the ones I've seen don't look very healthy to me, maybe 1 fish here and 1 fish there... What combination would work best 1 male and 2-3 females?

I was also looking at honey gouramis as well but didn't see them at the LFS... I'd like to make sure they are not very passive.

One area of concern with gouramis is the temperature difference between the tank and the air outside... I do have a lid on but it's not tightly closed at all. Right now the room temp is about 20 and the aquarium temp is 25.

I've been looking at dwarf Apistogrammas as well... interestingly enough and related to the water changes I've seen that it's recommended to do small water changes:

Apistogramma cacatuoides (Cockatoo Cichlid) — Seriously Fish

www.seriouslyfish.com

" very large water changes are best avoided with 10-15% weekly adequate provided the tank is lightly-stocked."

I'm likely to skip the ottos in the end... my wife didn't like them in the LFS...

 

[Byron]

Concerning the gourami...dwarf gourami are a serious health risk. Fish available in most fish stores, especially the chain stores, are a virus risk and should be avoided. If you can acquire fish direct from a reliable breeder, they should be OK. But otherwise, don't. Honey Gourami are better options. I've never heard of the water depth being an issue; most gourami remain in the upper half to third of the water, among floating plants. As for temp, provided the tank is covered the water above the surface should remain warm. Air-tight is not needed, but any normal tank cover unit, or a glass cover, is fine.

Re the water changes and apistogramma...it depends upon the parameters of your tank water compared to the source water. If they are reasonably identical, larger changes are beneficial. If the differences are significant, smaller-volume work better. "Parameters" here means GH, pH and temperature.

 

[Cmdr_DASh]

And a new invertebrate critter that I don't know what it is... looks like some sorf of a leech:

https://imgur.com/a/EExFFKH

Any ideas as to what this may be and if it's harmful? Thanks!

 

[Oblio]

I will have to check and possibly revise my article, as I thought the volume issue was discussed. In the interim, I can respond here.

As fish live in the tank of water, they significantly impact the water through their life processes. No aquarium can ever be even close to natural waters so we need to do things to counter the negatives. The tank water is continually being polluted by all sorts of things, from the obvious like fish waste and respiration, to less obvious like pheromones and allomones, none of which can be removed by any filter, only water changes and plants but the plants take time and most of us have way more fish in a tank for the plants to be successful on their own. I'll use arbitrary numbers to illustrate.

If fish are producing say 100 parts of pollution, changing 70% once a week removes 70 leaving 30. Changing 10% daily removes 10 leaving 90 on day one, then next day (water change) 10 leaving 90--but this is no where near even the first day's 10/90. The pollution is actually accumulating faster than it is being removed. Whereas the effect of the larger volume is to get rid of the majority of the pollution in one go, so the tank will have significantly less pollution going forward.

If I have my calculations right I show 10% daily stabilizing at a max of 139 parts after 22 days. Changing 70% weekly stabilizes at 143 parts at 4 weeks. 80%/wk gives a max of 125 parts. 72% weekly gives the same maximum parts of pollution as 10% daily.

Thinking through it it makes sense. Eventually the concentration grows to where 10% is equal to the fixed amount added each day. The same holds true for 70%/wk but the entire 100 is added to the tank before the water change so the max is greater. 80%/wk has a max of 125. All this of course also depends on the rate of pollution and what max level (and variance between changes) you are looking for.

I did this in Excel but could not attach the file.

 

[Oblio]

Bonus question for the geeky types:

What continuous water change rate would be required to keep the pollution level at 100 parts?

 

[Cmdr_DASh]

Bonus question for the geeky types:

What continuous water change rate would be required to keep the pollution level at 100 parts?

If fish produce 100 parts of pollution per week, they only way to stabilize at 100 per week by doing weekly changes is to change all the water.
With daily water changes you'll need to change about 14.25% of the water each day to stabilize at around 100 parts pollution.
Did I get it right?

 

[Cmdr_DASh]

Today I have:
- 12 cardinal tetras
- around 9 red cherry shrimp
- a handful of snails


I continue to research on fish that would be good additions and I've checked out several LFS. I continue to like dwarf gourami but one LFS told me that 50cm height is too much for dwarf gourami and their lungs can't take that depth - my actual water depth from substrate to surface doesn't exceed 40 cm, sounds like I should be fine. I still don't think I have a good source for dwarf gouramis... the ones I've seen don't look very healthy to me, maybe 1 fish here and 1 fish there... What combination would work best 1 male and 2-3 females?

I was also looking at honey gouramis as well but didn't see them at the LFS... I'd like to make sure they are not very passive.

One area of concern with gouramis is the temperature difference between the tank and the air outside... I do have a lid on but it's not tightly closed at all. Right now the room temp is about 20 and the aquarium temp is 25.

I've been looking at dwarf Apistogrammas as well... interestingly enough and related to the water changes I've seen that it's recommended to do small water changes:

Apistogramma cacatuoides (Cockatoo Cichlid) — Seriously Fish

www.seriouslyfish.com

" very large water changes are best avoided with 10-15% weekly adequate provided the tank is lightly-stocked."

I'm likely to skip the ottos in the end... my wife didn't like them in the LFS...

Gosh I'm having a hard time figuring out what fish to get ... looks like most larger fishes will want to eat my shrimps...
I'm searching for a pair of center fish + some bottom dwellers...
I'm now looking at apistogramma borellii and maybe some corys to complete the tank...

 

[Oblio]

If fish produce 100 parts of pollution per week, they only way to stabilize at 100 per week by doing weekly changes is to change all the water.
With daily water changes you'll need to change about 14.25% of the water each day to stabilize at around 100 parts pollution.
Did I get it right?

Correct, except I was looking at the continuous (not daily) change rate. It would be expressed in %tank/unit time. e.g. a pump with a required 2%/minute flow rate, for a 100 gallon tank, you require a 20 gal/minute pump to keep the level at 100. IOW, if you had a pump/filter that magically removed all pollutants, what flow rate would be needed? The engineer in me thinks that it will be a somehow related to e Euler's Number

We can see that as the time between changes is reduced, the size of the changes is also reduced. We should be able to solve for what the size of the change is when there is no change in time between them (i.e. continuous filtering).