Why does my tank smell?

smackitsakic

New Member
Joined
Oct 23, 2020
Messages
40
Reaction score
8
Location
Canada
I have noticed that my new 50 gallon tank smells. It’s in our basement and it definitely has an odour as soon as we go down the stairs. What are possible causes and fixes for that?

The tank is super clean and has new gravel. The ornaments and decor were brought over from my old 20 gallon, as well as the filter.

I had presumed the smell was just from cycling and would go away but it’s been about a month and no such luck. My water parameters are all reasonable. Thoughts?
 

mbsqw1d

Fish Gatherer
Tank of the Month!
Joined
Jul 28, 2009
Messages
2,344
Reaction score
2,257
Location
UK
What kind of smell? Most aquariums do have that typical aquarium scent that is 'earthy', due to the organics (i think)... I wouldn't say it's unpleasant.. anything unpleasant such as rotton egg smell would signify a problem, but i wouldn't expect that from a new setup
 
OP
S

smackitsakic

New Member
Joined
Oct 23, 2020
Messages
40
Reaction score
8
Location
Canada
What kind of smell? Most aquariums do have that typical aquarium scent that is 'earthy', due to the organics (i think)... I wouldn't say it's unpleasant.. anything unpleasant such as rotton egg smell would signify a problem, but i wouldn't expect that from a new setup
Yah it’s not anything rotten. I’d just describe it as stale/musty. It very well could just be the new norm with a bigger tank and will take some getting used to. Never notice it with a smaller tank so caught me off guard.
 

GuppyBreeder180604

Fish Fanatic
Joined
Aug 17, 2020
Messages
82
Reaction score
51
Location
mexico
maybe it is rotten food. Check the top of your water for any oily looks and if you have an oily look you should add a protein skimmer and try and clean your substrate as good as possible. Other thing that could cause the smell is a dead fish so check your stocking and count it, maybe is an algae bloom most probably cyanobacteria, if non of the things i said are the causen then try and do an 80% water change. Now please concider that a mature tank will always have a smell to it. but it is usually a really specific pond smell and it should only be detected when close to the aquiarium or when smelling it from the top. So you being able to smell it from across the room is kind of weird.
 
OP
S

smackitsakic

New Member
Joined
Oct 23, 2020
Messages
40
Reaction score
8
Location
Canada
maybe it is rotten food. Check the top of your water for any oily looks and if you have an oily look you should add a protein skimmer and try and clean your substrate as good as possible. Other thing that could cause the smell is a dead fish so check your stocking and count it, maybe is an algae bloom most probably cyanobacteria, if non of the things i said are the causen then try and do an 80% water change. Now please concider that a mature tank will always have a smell to it. but it is usually a really specific pond smell and it should only be detected when close to the aquiarium or when smelling it from the top. So you being able to smell it from across the room is kind of weird.
It could be algae of some sort. I’m keeping the light off most of the day to try to stop anything from growing. There has been some small blooms of green algae in spots. That could be partly to blame.
 

GuppyBreeder180604

Fish Fanatic
Joined
Aug 17, 2020
Messages
82
Reaction score
51
Location
mexico
It could be algae of some sort. I’m keeping the light off most of the day to try to stop anything from growing. There has been some small blooms of green algae in spots. That could be partly to blame.
yeah it may be that. when algae rots it smell awfull so once you get rid of it it will smell eve worse for a few days.
 

Koglin

Fish Crazy
Joined
Sep 13, 2020
Messages
243
Reaction score
292
Location
Denver, CO
It could be algae of some sort. I’m keeping the light off most of the day to try to stop anything from growing. There has been some small blooms of green algae in spots. That could be partly to blame.
When my tank started getting stinky I switched up my filtration, and also added a small media bag of purigen (I've read activated carbon will help with smell too though). The smell slowly died off after that - still has a slight earthy smell but only noticeable when I remove the lid for water changes.

I switched my filtration to:

Coarse/large pore intake sponge (1st mechanical)

Less porous bit of sponge above my impeller (2nd mech.)

Small media bag of purigen (I contribute this to being what really made the difference) *if you prefer to keep tannins in your water don't try this - it is very efficient at pulling them out.

Double layered white/blue poly fill (chem., 1 side is more coarse than the other, face the more condensed side towards the Purigen - in my case it was the blue side)

Ceramic cubes (bio.)

Also have a sponge on my outflow to help reduce surface agitation but that makes no difference with removing the smell.
 
OP
S

smackitsakic

New Member
Joined
Oct 23, 2020
Messages
40
Reaction score
8
Location
Canada
When my tank started getting stinky I switched up my filtration, and also added a small media bag of purigen (I've read activated carbon will help with smell too though). The smell slowly died off after that - still has a slight earthy smell but only noticeable when I remove the lid for water changes.

I switched my filtration to:

Coarse/large pore intake sponge (1st mechanical)

Less porous bit of sponge above my impeller (2nd mech.)

Small media bag of purigen (I contribute this to being what really made the difference) *if you prefer to keep tannins in your water don't try this - it is very efficient at pulling them out.

Double layered white/blue poly fill (chem., 1 side is more coarse than the other, face the more condensed side towards the Purigen - in my case it was the blue side)

Ceramic cubes (bio.)

Also have a sponge on my outflow to help reduce surface agitation but that makes no difference with removing the smell.
I don’t know what any of this means. ‍♂

I use the regular blue filters with carbon in them (that you can buy at Walmart). The aqua tech filter has a bio catching filter and then then penguin filter has the bio wheel. Do I need more than that? I can post pics if needed.
 

mcordelia

Fishaholic
Joined
Oct 22, 2020
Messages
402
Reaction score
242
Location
michigan
are you changing out all of the filter pads at once/how often do you change out filter pads? A lot of the beneficial bacteria in an aquarium live in the filter, so if you are only running 1 pad and then you change it out, you can accidentally cause your tank to re-cycle. Also, carbon doesn't last very long in an aquarium, so you may be better off buying carbon separately and only rinsing out the pad (in water from the tank that you took out during the water change) and changing out the carbon itself, instead of buying a whole new pad with the carbon inside.
 

GuppyBreeder180604

Fish Fanatic
Joined
Aug 17, 2020
Messages
82
Reaction score
51
Location
mexico
I don’t know what any of this means. ‍♂

I use the regular blue filters with carbon in them (that you can buy at Walmart). The aqua tech filter has a bio catching filter and then then penguin filter has the bio wheel. Do I need more than that? I can post pics if needed.
what i do and it was worked quite well is that in the media chamber i have a coarse sponge and some lava rocks as biological filter, as a mechanical filter i use polyfill just outside the intake tube (make sure the polyfill is not fire retardant since that will pollute your water), i do not use activated carbon but for your case i woul recomend a bag of it between the polyfill and the sponge.
 

GuppyBreeder180604

Fish Fanatic
Joined
Aug 17, 2020
Messages
82
Reaction score
51
Location
mexico
are you changing out all of the filter pads at once/how often do you change out filter pads? A lot of the beneficial bacteria in an aquarium live in the filter, so if you are only running 1 pad and then you change it out, you can accidentally cause your tank to re-cycle. Also, carbon doesn't last very long in an aquarium, so you may be better off buying carbon separately and only rinsing out the pad (in water from the tank that you took out during the water change) and changing out the carbon itself, instead of buying a whole new pad with the carbon inside.
so true, you should only clean your filter once a month in aquiarium water from a water change, if you just toss it in to the trash you get rid of lots and lots of beneficial bacteria.
 

Naughts

Fish Herder
Joined
Jun 2, 2019
Messages
1,061
Reaction score
667
Location
UK
I agree that activated carbon (refresh monthly) or Purigen should reduce the smell.

It's also worth checking around the tank for the source of the smell too. A small leak or water sat in a hose will give off a musty smell.
 

Koglin

Fish Crazy
Joined
Sep 13, 2020
Messages
243
Reaction score
292
Location
Denver, CO
I don’t know what any of this means. ‍♂

I use the regular blue filters with carbon in them (that you can buy at Walmart). The aqua tech filter has a bio catching filter and then then penguin filter has the bio wheel. Do I need more than that? I can post pics if needed.
Haha no worries, it took me a good bit of reading to understand it better and decide how I wanted to customize my filtration.

Don't fret: the filtration you have is fine, I'll try to explain a little more depth and it can actually save you $ in the long run. Afterward, I'll edit the post with a couple articles if you're interested.

So your filtration goes in stages. Not sure you have a mechanical stage though.

1st stage: mechanical - typically a intake sponge or a sponge after your impeller (or both) and before your other filters. Used to pull out and catch larger debris (just rinse off in dirty tank water every now and again) and other large particulate matter. I use both for a 2 stage mechanical filtration.

2nd stage: chemical - typically the pads (in your case the blue pads with carbon in them). Used to catch dissolved pollutants. I use a dual-sided filter floss (polyfill basically) for a 2 stage chemical.

3rd stage: biological. Houses 1 source of your bacteria (also sources present in the substrate and some in water, but we use the filter bio media as a "homestead" for the bacteria). The key to the bio media is: the more surface area the better (more room for your beneficial bacteria). I use the ceramic bio cubes (look like small cylinders) and place them all facing the same direction (point so water goes through the hole) and cram as many as you can fit. *Edit - a lot of filters come with a type of plastic screen/sheet to work as biological filtration, feel free to scrap that and replace with something better (replace smartly though).

By customizing these you can increase the effectiveness of your filter. In your case - you use the blue pads with carbon in them. Which is fine - but activated carbon has a lifespan, and once spent when you change out the pad with carbon in it - you can affect your cycle. Always best to reuse filters for a long time, just can't do that really with filters that have carbon inside them. Activated carbon will pull out some chemicals, tannins, and some nutrients that your plants use (generally not enough to affect plant growth), so it does help to clean water - just doesn't last forever.

To save money, and help your beneficial bacteria - you can buy a large sheet of dual sided polyfill (will work as a 2 stage chemical filter) and cut out the sizes of filter you need (link below to an example of this). The sheet will last forever. Then you could switch to a small media bag and fill it with Purigen (I suggest) or activated carbon and place it before the poly. This way, you can change out the carbon/Purigen without changing the chemical filter (which also houses beneficial bacteria). During times you do need to change the chem filter, simply place a new on in the filter a few days before pulling out the old one.

Purigen also lasts a long time - and it can be cleaned/"recharged" for further use. I just bought the bag that treats 100 gallons, split it in 2, and put in media bags. Before taking 1 out for "recharging" I put the 2nd one in a few days beforehand (same as the filter floss).

I'm not the best at explaining stuff and will link some articles. Hope this helped to explain how filtration works a bit more - there are options within each stage to customize it to suit your needs.

*Edit:

HOB customization video - full of info.


*Edit: HOB customization guide (uses a topfin silentstream filter and explains various ways to customize, but all hob filters can be similarly customize, I have 3 customs filters: a topfin silentstream, a Fluval Aquaclear, and an aqueon slow-flo for shrimp - all 3 are designed different but all have same custom filtration).


*2nd edit: explanation of filtration stages


Product links for a few things:



Purigen works in these media bags but the link for the Purigen I tried is broke. Its like $13.00 for a bag that treats 100 gallons (split between your own media bags). My custom filtration helped my water clarity a lot, but it's really the Purigen I credit for pulling out the smell.
 
Last edited:
Top