Stocking Levels

[Peteinhull]

This has probably been discussed on more than one occasion, but I'm fairly new to this and I'm starting to get a bit confused!

I have a Interpet Fishbox (now called FishPod I believe) 64 Litre tank, the rough surface area is (in cm) 60 x 30 which is 1800 sq cm. So based on the stocking levels advice given in 10 Rules For Healthy Fishkeeping this means that I can keep 150cm of fully grown fish.

Another article I read on here suggests that you allow 1" of fish for every us gallon of water. So for example if your tank is 20 gallons, you can have 20" of fish in total. Using this equation, my 64L is 16.9 US Gallons which equals 16.9" of fish or 42.9 cm.

Obviously one is over three times the other, so which one is correct?

Any help would be appreciated.

Sorry if I've posted this in the wrong place or indeed repeated a previous post.

 

[eaglesaquarium]

Stocking is a discussion that people will always debate. Ultimately it comes down to how much maintenance you are willing to put in. If you "overstock" according to one metric slightly, but do more frequent and larger volume water changes, it should be fine. On the other hand, if you "understock" by that same metric and don't do frequent or large enough water changes then you are inviting trouble.



The key for lack of a better on is your tanks nitrates (although there is far more going on in the tank than just that). You want to keep your nitrates at a fairly static and low value - the standard is to shoot for about 20-40ppm over your tap water conditions.


If it were me, I'd start with the first stocking level - that's the metric I use. But, then if your water quality stays high and you have a few more fish you wanted to add, go ahead. The one thing you don't want to do though is load up too many fish all at once and be forced to rehome them. Start small and expand if things remain stable and you feel you can add more. But, I would see what 17 inches of fish looks like in your tank before going for triple that.


(Also, be certain that the fish you get are appropriate for that size tank. None of them should be very big (less than 3 inches), nor should any of them be overly active swimmers (like zebra danios).

 

[Kelly-Jo]

Hi

The guides about 1" of fish per gallon etc are really only guidelines for beginners and in practice are not all that useful. For example, this particular guideline does not take into account the body size or bulk of the fish (i.e: 10 1" tetras in a 20 gallon is NOT the same as 1 10" Oscar)

Maybe if you wanted you could suggest some fish that you like or have seen and we will be able to tell you if they are appropriate for your tank size? We could give yous some other thoughts too?

 

[Peteinhull]

Thanks for the replies.

eaglesaquarium: Good info and advice, thanks.

Kelly-Jo: Also good advice.

My current stock of fish is as follows:

2 x Guppy - Poecilia reticulata (Male);
2 x Endler - Poecilia wingei(Male);
3 x Platy - Xiphophorus maculatus (1M + 2F);
1 x Zebra Danio - Danio Rerio;
1 x Pearl Danio - Danio Albolineatus;
2 x Harlequin Rasbora - Trigonostigma Heteromorpha;
3 x Neon Tetra - Paracheirodon Innesi.

Now having read (A LOT) on this forum, I now know I need to increase my Harlequin Rasbora to at least 6. I was also considering Corydoras Leucomelas. I want to keep more smaller breads like Cherry Barbs or other Tetra.

Any thoughts?

 

[Man of fish]

You should also bump the neons to six as well and if it were me I'd remove the dan because they need around 4ft. Tank. Although they're small they like room to dart and zip around.

 

[Kelly-Jo]

Thank you for giving us your ideas.

I think firstly you should remove the danios and tetras. Danios ideally need a 4ft long tank as they are shoaling fish that need a great deal of swimming space as they are increadibly active, the same with tetras. I personally also wouldn't have harlequin rasbora in a 65L, it's a touch on the small side IMHO. The endlers are a good option and also the guppies. I would advice against male and female platys in the same tank unless you want to breed them as you will soon be overrun with fry.

How about something like this?

4 x Endler
3 x Oto

Otos are nice little catfish which can be housed in tanks of 10G and over. They need to be fed algae wafers and vegetables. They will also eat small amounts of algae in the tank but it should not be their staple as they will starve. Just a thought, if you like the look of them

 

[Peteinhull]

You should also bump the neons to six as well and if it were me I'd remove the dan because they need around 4ft. Tank. Although they're small they like room to dart and zip around.

Yes, I read on here that they need a large tank, a shame that the local tropical fish supplier didn't tell me that before I put them in our small 27 litre tank where they spent the last 3 years, this new tank must seem like a sea to them!

Incidently, my Zebra Danio has over the years developed a quite severe curvature or hump of the spine, could this have had anything to do with the size of the tank? He seems happy enough and feeds, swims and interacts well, the Pearl Danio doesn't display the same issue.

 

[Kelly-Jo]

The curvature of the spine is usually due to temperature shock. Has the fish been exposed to sudden blasts of particularly cold water? Perhaps after water changes? If not, does the temperature of the tank fluctuate a great deal?

 

[Man of fish]

It's probably an effect of the small tank I'm afraid. When fish even small ones are put in too small of a tank, it stunts their growth. Meaning they stop growing but not on the inside. Their internal organs will continue to grow which is probably what this is.

 

[Peteinhull]

Here's a quick phone pick of the Zebra Danio:

As you can see it's quite pronounced.

The curvature of the spine is usually due to temperature shock. Has the fish been exposed to sudden blasts of particularly cold water? Perhaps after water changes? If not, does the temperature of the tank fluctuate a great deal?

No temperature has always been constant.

 

[Kelly-Jo]

It definitely looks to me like temperature shock which is usually due to excessive cooling rather than a sudden heat rise. If he had this when you acquired him it could just simply be a birth deformity. Otherwise, I would say that I'm 95% certain that is what it is. Do you add cold tap water into the tank whilst performing changes or do you make sure the temperature is the same as the tank water? Unfortunately, there isn't much you can do to rectify his curvature and as long as he is able to swim and find food, there shouldn't be too much of an issue with it other than aesthetically. If you notice he is struggling to swim or seems to be in pain because of it then you may need to take action, but for now I would try to keep the fish at a stable level if you aren't already and ensure they are not exposed to sudden rises or drops in temperature.

 

[Peteinhull]

It definitely looks to me like temperature shock which is usually due to excessive cooling rather than a sudden heat rise. If he had this when you acquired him it could just simply be a birth deformity. Otherwise, I would say that I'm 95% certain that is what it is. Do you add cold tap water into the tank whilst performing changes or do you make sure the temperature is the same as the tank water? Unfortunately, there isn't much you can do to rectify his curvature and as long as he is able to swim and find food, there shouldn't be too much of an issue with it other than aesthetically. If you notice he is struggling to swim or seems to be in pain because of it then you may need to take action, but for now I would try to keep the fish at a stable level if you aren't already and ensure they are not exposed to sudden rises or drops in temperature.

Thanks for the info. No, I always try to ensure that the replacement water is the same by adding hot water (yes, I know, another thing I've found out whilst reading the forum! I won't do it again!!) to the cold to get it somewhere near to the original temp.

I don't think he displayed any disfigurement when we got him, but we did get the Pearl Danio at the same time and he's fine.

Someone once said that it could have been due to fish TB? But to be fair the explanation given by Man of Fish seems to fit better.

 

[eaglesaquarium]

Thanks for the info. No, I always try to ensure that the replacement water is the same by adding hot water (yes, I know, another thing I've found out whilst reading the forum! I won't do it again!!) to the cold to get it somewhere near to the original temp.

Why not? Is it because of the copper myth? There is no reason NOT to use a mixer tap to refill your tank. Just make sure that the temp matches closely, or that if anything it is slightly BELOW the temp of your tank. Your heater can make up the difference, and if it is added slowly, the fish are just fine with it, as it emulates a rainfall.

 

[Kelly-Jo]

Fish TB is a possibility as it does cause skeletal deformities.

If this is the case, be careful with any open wounds whilst you are performing tank maintenance. In the unlikely event that it is Fish TB, I believe (someone may want to correct me if I'm wrong) there is a chance of the myobacteria affecting humans if they have open cuts or wounds.

 

[minnnt]

+1 on eaglesaquarium. I always mix my water with the hot water tank.