How many fish can i have in my tank?

[Knee-u-bee]

I have a 20 long, i have 7 cichlids all about 2-2 1/2 inch long, 1 crayfish, 1 suckerfish - 3 in long.

I bought a filter that said it filters out 20-50 gallon tanks.

I have to clean out my tank every week, if not i get brown milky slim in the bottom of the tank and in my filter. Is that alge? I thought alge was green. Could this be cuz my filter get sun shine all day long and it rapids the growth of this brown milky stuff? Or do i have to many fish in such a small tank?

Any suggestions and info would be great.

[gt3guru]

Re: How many fish can i have in my tank?

sunlight and hood lights are a big cause of algea, it comes in all forms not just green.

the rule of thumb is one inch of fish per gallon. though usually you want to go by the max size so they have room to grow. If you are willing to test your water and do all the appropriate water changes I say go ahead and overstock, just be aware it may require ALOT of water changes. Do you know what your ammonia/nitrite/nitrate levels are?

Sence those fish are going to at least double in size I'd suggest starting to make room for at least a 55 gallon tank in your future.

For now  maybe find a way to keep some sunlight out, maybe an aquarium backing. It could also be over feeding. make sure none of the food is getting to the bottom.

[eklikewhoa]

Re: How many fish can i have in my tank?

Most cichlids require much more room then a 20g and much more filtration....rule of thumb for cichlid filtration is ~10x overturn so you would need something around 200gph

What kind of cichlids are they?

[PhishPhreek]

Re: How many fish can i have in my tank?

If your fish are swimming around and having a good time then you don't have too many in the tank.

If your fish are swimming at the surface and gasping for air then you have too many.  A tempory fix is to add an air stone or box filter that stirs up the water on the surface allowing the water to exchange CO2 and O2 at a faster rate.   But the long term fix is to get a bigger tank or less fish.

[Knee-u-bee]

Re: How many fish can i have in my tank?

sunlight and hood lights are a big cause of algea, it comes in all forms not just green.

the rule of thumb is one inch of fish per gallon. though usually you want to go by the max size so they have room to grow. If you are willing to test your water and do all the appropriate water changes I say go ahead and overstock, just be aware it may require ALOT of water changes. Do you know what your ammonia/nitrite/nitrate levels are?

Sence those fish are going to at least double in size I'd suggest starting to make room for at least a 55 gallon tank in your future.

For now  maybe find a way to keep some sunlight out, maybe an aquarium backing. It could also be over feeding. make sure none of the food is getting to the bottom.

I have a "blue" light, it's not really a white light. Does that matter?

I do have a backing on the tank, and the only thing that gets exposed to the sun is the filter. I have not recently checked my levels. Everytime i feed them they leave very little to waste.

U think i should use some kind of shield on the filter to keep the sun from hitting it?

Most cichlids require much more room then a 20g and much more filtration....rule of thumb for cichlid filtration is ~10x overturn so you would need something around 200gph

What kind of cichlids are they?

4 cobalt blue, 1 electric yellow, 1 black convict, and the others i havent had a chance to find out.

[Mzungu]

Re: How many fish can i have in my tank?

You'll definitely need a bigger tank.  

I don't think you need to cover the filter. If it is in fact algae growing in there, that's probably a good thing as it will eat up some of the nitrates, as well. What kind of filter is it? Does it have a top? Or is it clear plastic?

However, not sure what you mean by brown milky slime...but it could be just beneficial bacteria in the filter, which is good to have. Regardless, it's a good idea to clean your tank every week, if that means a water change and a little maintenance. Make sure you're not doing huge water changes and replacing your filter media at the same time each week. If debris is at the bottom of the tank, I'd watch your feeding, especially since it seems like you have quite a bioload in there.

The light should be okay, but for how long are you leaving it on? Longer photoperiods can contribute to excess algae, as well.

[Knee-u-bee]

Re: How many fish can i have in my tank?

You'll definitely need a bigger tank.  

I don't think you need to cover the filter. If it is in fact algae growing in there, that's probably a good thing as it will eat up some of the nitrates, as well. What kind of filter is it? Does it have a top? Or is it clear plastic?

However, not sure what you mean by brown milky slime...but it could be just beneficial bacteria in the filter, which is good to have. Regardless, it's a good idea to clean your tank every week, if that means a water change and a little maintenance. Make sure you're not doing huge water changes and replacing your filter media at the same time each week. If debris is at the bottom of the tank, I'd watch your feeding, especially since it seems like you have quite a bioload in there.

The light should be okay, but for how long are you leaving it on? Longer photoperiods can contribute to excess algae, as well.

It is a AquaClear filter, yes it has a top and yes it is clear plastic.

I am feeding like i read somewhere to feed as much as they can consume in 3 min. and i do a 5 gallon change everytime i do water change.

I leave the light on from like 9am -10pm, sometimes i forget to turn it on, and turn it on @ 6-10ish. Yeah, i know it can sontribute to the alge growth, thats why i was thinking it's growing to much in the filter since it has sunshine all day long. ( I leave my blinds open for them)

So as is stands now, i need to get a bigger tank or get rid of some of the fish, and give it a little less light.?

[eklikewhoa]

Re: How many fish can i have in my tank?

You need to cut the light back a whole lot! I have planted tanks that don't get as much light as your tank does.

but yeah......bigger tank/less fish and a lot less light.

[Knee-u-bee]

Re: How many fish can i have in my tank?

You need to cut the light back a whole lot! I have planted tanks that don't get as much light as your tank does.

but yeah......bigger tank/less fish and a lot less light.

How many hr's of light should it be? Does my blue light still contribute to the alge growth? Cuz the fish store said it cant be used with plants, so i figured it would be the same for alge growth.

[Mzungu]

Re: How many fish can i have in my tank?

Algae will pretty much grow in any kind of light whatsoever.  :)

I would cut your light back to around 10 hrs a day, if possible. Some do less, some do more. But over 12 hrs is an invitation for lots of algae. A good idea is to get a timer, that way your fish can be on a schedule, and you can base that schedule on yours. I have mine turn on after I've left for work, that way I can come home and feed/watch/etc.

[Knee-u-bee]

Re: How many fish can i have in my tank?

Algae will pretty much grow in any kind of light whatsoever.  :)

I would cut your light back to around 10 hrs a day, if possible. Some do less, some do more. But over 12 hrs is an invitation for lots of algae. A good idea is to get a timer, that way your fish can be on a schedule, and you can base that schedule on yours. I have mine turn on after I've left for work, that way I can come home and feed/watch/etc.

Yeah, thats what i did today, while i was @ work it was off, i got home and feed the fish and turned the light on, im ganna leave it on till it's time to sleep.

Thanks for the assistance, this forum is THE best.