Is my tank nearly fully stocked?

[steelo]

Hi everyone,

I have a 45 gallon that currently has: 12 neon tetras, 6 rasboras, a pleco that shouldn't grow over 4-5", 2 sparkling guaramis and some live grass. I was thinking about adding 6 more rasboras, but will that be overdoing it?

The tank has been stocked for 2 weeks, I changed 25% of the water 2 days ago and nitrates don't ever exceed 5 ppm.

 

[FishGuest5123]

You are probably ok but a good tool to use is on aqadvisor.com.

 

[steelo]

You are probably ok but a good tool to use is on aqadvisor.com.

Thanks, it says, based on my filtration, dimensions and current stocking that I am 73% stocked, filtration is 110% and they recommend 16% water changes every week (although I will do at least 25%-50% every week). If I add 6 more rasboras, I'll be 88% stocked and filtration will be 102%. Pretty cool tool!

 

[eaglesaquarium]

I do not trust what aqadvisor recommends.

6 more rasboras will be ok, but you will need to increase your water change volumes - 50% would be recommended at that point.

 

[Darran Beal]

Thanks, it says, based on my filtration, dimensions and current stocking that I am 73% stocked, filtration is 110% and they recommend 16% water changes every week (although I will do at least 25%-50% every week). If I add 6 more rasboras, I'll be 88% stocked and filtration will be 102%. Pretty cool tool!

Ignore the previous answers. You are well under stocked. You can add many more fish. Secondly only do a 20% water change every week, any more than that and you will remove much needed good bacteria. Thirdly have a good filtration system at least 50% more than the filter instructions. Enjoy your fish.

 

[Colin_T]

For the OP.

What are the tank dimensions (length x width x height)?
How long has the tank been set up for?
What sort of filter do you have and is it cycled?
How often do you feed the fish and what do you feed them?
How often do you do water changes and how much do you change (25% every week or something else)?
What species of rasbora do you have (some grow bigger than others)?
What species of pleco do you have and what do you feed it?
Do you have driftwood in the tank for the pleco to graze on?
How many plants and what species of plant do you have (some plants are better at removing nutrients)?
How long is the tank light on for?

The above questions are all related to stocking density in aquariums. You can have a long wide tank with lots of plants and 200 neon tetras and they will be fine if fed once a day and you do a 75% water change and gravel clean the substrate every week. However, if you fed the fish 5 times a day and only did a 25% water change every month it would end in disaster.

Basically the more fish you have in the tank, and the bigger the fish get, and the more food you put into the tank, the more water changes you need to do to keep everything alive and well. You also need to make sure the water chemistry (pH & GH) and the temperature are correct for all the species in the tank. And you need to make sure all the fish get along together and there is no stress from bullying or territorial behaviour.

--------------------------

Secondly only do a 20% water change every week, any more than that and you will remove much needed good bacteria.

Most of the beneficial bacteria live on solid objects like gravel, glass, plants and filter materials. There is less than 1% of beneficial filter bacteria in the water.

You can change 100% of the aquarium water and replace it with dechlorinated water that has a similar temperature and chemistry to the old tank water, and it will not affect the filter bacteria in an established tank. However, you should not remove all the water otherwise the fish get damaged by the substrate when they are out of water.

Aquarium fish live in a soup of microscopic organisms, and most of them are harmful to the fish. So if you are trying to dilute nutrients or disease organisms in the aquarium, then a 75% water change will be more effective than a 25% water change.
If you remove 25% of the water you leave 75% of the nutrients and disease organisms behind.
If you change 50% of the water you leave half the nutrients and disease organisms behind.
If you change 75% of the water you leave 25% of the nutrients and disease organisms behind.

I have been doing 50-90% water changes every week for over 30 years and never had any problems with filter bacteria dying due to the large water changes.

 

[eaglesaquarium]

Ignore the previous answers. You are well under stocked. You can add many more fish. Secondly only do a 20% water change every week, any more than that and you will remove much needed good bacteria. Thirdly have a good filtration system at least 50% more than the filter instructions. Enjoy your fish.

Welcome to the forum Darran.

Unfortunately, your response indicates a misunderstanding in the beneficial bacteria of the aquarium... the bacteria live inside a biofilm, on the surfaces of the tank... any surface can house them, though generally they prefer to live in areas that meet all their needs for survival... ammonia/nitrite, oxygen, inorganic carbon, etc. Which often means that they live on surfaces that see a lot of water turnover... this means the vast majority (but not totality) of them live in and around the filter.


Second, increasing the fish bioload as you suggest, coupled with only a 20% water change weekly will result in a rapid increase in organics within the fish tank. This can lead very quickly to 'Old Tank Syndrome'.


Lastly, increasing the filtration system does not change the above facts. Over filtering the water just means that you are moving more volume of water over the filtration surfaces, it does nothing to change the fact that there are more organics in the water and can cause more harm than good. Having filters move around water with high levels of nitrate does nothing to remove the nitrate. And nitrate is not the only thing we are looking to remove, though it is a good indicator of bioload.

 

[FishGuest5123]

Eaglesaquarium, proud to have you as a moderator! Your explanation is spot on. 20% water changes are not enough to keep your nitrates down. Removing good bacteria and controlling nitrates are not one in the same. I do a weekly 70% w/c and my cycle is not affected. As stated above and thoroughly agreeing, the beneficial bacteria is on the filter media, substrate, sides, decor. Very little is in the water itself and changing it won’t harm the good bacteria or stress the fish. In fact, my fish get excited with their water changes and welcome them. They even play in the bubbles as new water is going in. Good luck!

 

[FishGuest5123]

For the OP.

What are the tank dimensions (length x width x height)?
How long has the tank been set up for?
What sort of filter do you have and is it cycled?
How often do you feed the fish and what do you feed them?
How often do you do water changes and how much do you change (25% every week or something else)?
What species of rasbora do you have (some grow bigger than others)?
What species of pleco do you have and what do you feed it?
Do you have driftwood in the tank for the pleco to graze on?
How many plants and what species of plant do you have (some plants are better at removing nutrients)?
How long is the tank light on for?

The above questions are all related to stocking density in aquariums. You can have a long wide tank with lots of plants and 200 neon tetras and they will be fine if fed once a day and you do a 75% water change and gravel clean the substrate every week. However, if you fed the fish 5 times a day and only did a 25% water change every month it would end in disaster.

Basically the more fish you have in the tank, and the bigger the fish get, and the more food you put into the tank, the more water changes you need to do to keep everything alive and well. You also need to make sure the water chemistry (pH & GH) and the temperature are correct for all the species in the tank. And you need to make sure all the fish get along together and there is no stress from bullying or territorial behaviour.

--------------------------

Most of the beneficial bacteria live on solid objects like gravel, glass, plants and filter materials. There is less than 1% of beneficial filter bacteria in the water.

You can change 100% of the aquarium water and replace it with dechlorinated water that has a similar temperature and chemistry to the old tank water, and it will not affect the filter bacteria in an established tank. However, you should not remove all the water otherwise the fish get damaged by the substrate when they are out of water.

Aquarium fish live in a soup of microscopic organisms, and most of them are harmful to the fish. So if you are trying to dilute nutrients or disease organisms in the aquarium, then a 75% water change will be more effective than a 25% water change.
If you remove 25% of the water you leave 75% of the nutrients and disease organisms behind.
If you change 50% of the water you leave half the nutrients and disease organisms behind.
If you change 75% of the water you leave 25% of the nutrients and disease organisms behind.

I have been doing 50-90% water changes every week for over 30 years and never had any problems with filter bacteria dying due to the large water changes.

Well said, Colin!

 

[Byron]

I concur with the advice of Colin and eagles re water changes and stocking.

As for tools like aqadvisor...it is frankly impossible to build a reliable system program that will calculate fish load in a given aquarium because there are so many factors and it takes human thought. Factors that must be considered are the obvious ones like aquarium size (dimension and also volume as these are two very different things and both are crucial), size of the mature fish, filtration. But there are other factors that have just as much impact, such as the aquascaping itself (substrate, décor, plants), light, fish species and numbers of each (not related to the fish mass aspect), the different species in the tank (activity level of each species must be compatible, plus their normal interactive levels within the group and with other species), water parameters. These are the factors that come to mind, and I would like to see aqadvisor or any other program accurately dealing with all of these to arrive at the answer. There is still a need for human intelligence and each aquarium is unique.

 

[steelo]

Thanks, for now I'm going to increase it from 25% to 35% (14 gallon) weekly changes. As of right now, I am having to add dechlor directly to the tank and then fill up milk jugs one by one to replace the 10 or so gallons I removed. I fear that this already stresses the fish out a great deal and replacing half of the water every week could be catastrophic if the chlorine isn't immediately eradicated.

It's also very tedious because I'm having to fill up a 2 gallon bucket and carry it 5-6 times to the kitchen to dump. Unfortunately, using the faucet siphon isn't an option with the type we have...

I only feed once a day and am extremely careful not to give more than a pinch of flakes (I treat them to blood worms once a week). I think based on the answers given that I will keep my current stock and not add any more fish.

I do worry that it may not be stocked enough to maintain the nitrite bacteria and could mini-cycle.

 

[steelo]

For the OP.

What are the tank dimensions (length x width x height)?
How long has the tank been set up for?
What sort of filter do you have and is it cycled?
How often do you feed the fish and what do you feed them?
How often do you do water changes and how much do you change (25% every week or something else)?
What species of rasbora do you have (some grow bigger than others)?
What species of pleco do you have and what do you feed it?
Do you have driftwood in the tank for the pleco to graze on?
How many plants and what species of plant do you have (some plants are better at removing nutrients)?
How long is the tank light on for?

The above questions are all related to stocking density in aquariums. You can have a long wide tank with lots of plants and 200 neon tetras and they will be fine if fed once a day and you do a 75% water change and gravel clean the substrate every week. However, if you fed the fish 5 times a day and only did a 25% water change every month it would end in disaster.

Basically the more fish you have in the tank, and the bigger the fish get, and the more food you put into the tank, the more water changes you need to do to keep everything alive and well. You also need to make sure the water chemistry (pH & GH) and the temperature are correct for all the species in the tank. And you need to make sure all the fish get along together and there is no stress from bullying or territorial behaviour.

--------------------------

Most of the beneficial bacteria live on solid objects like gravel, glass, plants and filter materials. There is less than 1% of beneficial filter bacteria in the water.

You can change 100% of the aquarium water and replace it with dechlorinated water that has a similar temperature and chemistry to the old tank water, and it will not affect the filter bacteria in an established tank. However, you should not remove all the water otherwise the fish get damaged by the substrate when they are out of water.

Aquarium fish live in a soup of microscopic organisms, and most of them are harmful to the fish. So if you are trying to dilute nutrients or disease organisms in the aquarium, then a 75% water change will be more effective than a 25% water change.
If you remove 25% of the water you leave 75% of the nutrients and disease organisms behind.
If you change 50% of the water you leave half the nutrients and disease organisms behind.
If you change 75% of the water you leave 25% of the nutrients and disease organisms behind.

I have been doing 50-90% water changes every week for over 30 years and never had any problems with filter bacteria dying due to the large water changes.

Hi Colin,

It is a 45 gallon tank, 36 1/4" x 12 5/8" x 23 3/4"

Tank is cycled, did a fishless cycle that lasted almost 3 months

Filter is a aqueon quietflow 30

Light is set on a timer but on for 12 hours a day, mainly for the plants

Feed fish flakes once a day, blood worms once a week

They are harlequin rasboras

No driftwood

Unsure about the type of pleco (bristlenose maybe) but was told by the fish shop that it won't grow larger than 4-5"

I honestly don't remember the type of plants, one is a grass type plant that doesn't grow too tall, the other has long wavy leaves that kind of fall over when it grows too tall.

 

[Byron]

Thanks, for now I'm going to increase it from 25% to 35% (14 gallon) weekly changes. As of right now, I am having to add dechlor directly to the tank and then fill up milk jugs one by one to replace the 10 or so gallons I removed. I fear that this already stresses the fish out a great deal and replacing half of the water every week could be catastrophic if the chlorine isn't immediately eradicated.

A 35% change is certainly better than 25%, but it could be more and the fish would without question be better for it. You seem to have a few misunderstandings, perhaps we can explain them better.

I can guarantee that the more water you change the less stressed and healthier the fish will be. The less water changed, the more stress from living in "old" water will increase.

Water conditioners instantly dechlorinate. I use API's Tap Water Conditioner which is the most highly concentrated commercial dechlorinator in the hobby. As you are using buckets to re-fill, it would bee easier to add the drops of dechlorinator to each bucket as it fills, then pour that into the tank. I do this with my smallest tank, a 10g, which tends to overflow if I use the Python attached to the tap. I drain out two buckets of water which amounts to 6 gallons, fill each under the tap and add three drops of the API as the bucket fills, then use a jug to dip in the bucket and fill the tank as I can control the flow more easily. On the other tanks which are filled with the Python, I start the water flow into the tank at the correct temperature and then add the required drops for the approximate volume removed/added. In 25+ years I have never had problems.

I do worry that it may not be stocked enough to maintain the nitrite bacteria and could mini-cycle.

Once the nitrifying bacteria establish, they will remain at the level sufficient for the "food" available, being ammonia and then nitrite. Unless you do something tragic that kills the bacteria (medications can, for example) you are not going to have mini-cycles. This only occurs when you suddenly overload thee system such that ammonia increases more rapidly than thee bacteria can multiply or handle.

Live plants are a good safeguard; they take up ammonia/ammonium rapidly, especially fast growing plants and floating plants are the best for this.

 

[Byron]

No driftwood

Unsure about the type of pleco (bristlenose maybe) but was told by the fish shop that it won't grow larger than 4-5"

You must have real wood in the tank for Bristlenose. They "eat" the wood not as nutritional food but it is essential for the bacteria in their digestive system.

I use Malaysian Driftwood which you can buy at some fish stores and online. It is dark brown, heavy so it immediately sinks, and safe. You can get pieces that have tunnels and crevices which are ideal for plecos and similar fish. Cories and loaches also need this.

 

[steelo]

A 35% change is certainly better than 25%, but it could be more and the fish would without question be better for it. You seem to have a few misunderstandings, perhaps we can explain them better.

I can guarantee that the more water you change the less stressed and healthier the fish will be. The less water changed, the more stress from living in "old" water will increase.

Water conditioners instantly dechlorinate. I use API's Tap Water Conditioner which is the most highly concentrated commercial dechlorinator in the hobby. As you are using buckets to re-fill, it would bee easier to add the drops of dechlorinator to each bucket as it fills, then pour that into the tank. I do this with my smallest tank, a 10g, which tends to overflow if I use the Python attached to the tap. I drain out two buckets of water which amounts to 6 gallons, fill each under the tap and add three drops of the API as the bucket fills, then use a jug to dip in the bucket and fill the tank as I can control the flow more easily. On the other tanks which are filled with the Python, I start the water flow into the tank at the correct temperature and then add the required drops for the approximate volume removed/added. In 25+ years I have never had problems.



Once the nitrifying bacteria establish, they will remain at the level sufficient for the "food" available, being ammonia and then nitrite. Unless you do something tragic that kills the bacteria (medications can, for example) you are not going to have mini-cycles. This only occurs when you suddenly overload thee system such that ammonia increases more rapidly than thee bacteria can multiply or handle.

Live plants are a good safeguard; they take up ammonia/ammonium rapidly, especially fast growing plants and floating plants are the best for this.

Thanks! I'm using tetra dechlorinator. The directions state to use 5 mL per 10 gallons (so 1/2 a mL for 1 gallon) I'm using 1 gallon milk jugs to refill, how many drops would you estimate I need to add per gallon? That's like 1/8 of a teaspoon. LOL