Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

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You can't do that!!!

Perch, Perca fluviatilis
Can you keep a Perch



The majority of fish in the hobby today are commercially bred for the hobby with different species from all over the globe being bred next to each other in the same quality of water. Yet if it is suggested that a fish whose ancestors came from a region where the pH is 7 - 7.5 should be kept in the same tank as a fish whose ancestors lived in water where the pH was 6 - 6.5 then rest assured you'll be told that it is wrong and possibly even that it is cruel. Yet both species are being bred in the same water and have been for many many generations.

With a little research and a dash of common sense this would be easy to find out by anyone. Water with a pH between 6.5 and 7.5 with a little leeway on either side will satisfy the vast majority of captive bred fresh water fish with just a few exceptions like Rift Valley Cichlids for example.

Wild fish are entirely different, every attempt should be made to replicate their natural environment especially when it comes to water chemistry.

Taking it a little further, some fish have actually evolved to thrive in the water which they have been bred in rather than the water where the species originates. Discus are commonly kept in water with a pH of 6.5 to 7.5, they live a long life if cared for properly and will breed easily and successfully in such water. Yet some wild Discus come from regions where the pH could fall below 4 at certain times of the year. If a tank bred Discus was kept at pH 4 or less it would die quite quickly in all probability.

In short, try to avoid extremes of pH, learn if your fish have any special requirements such as the previously mentioned Rift Valley Cichlids, Black Mollies, Pufferfish and so on and keep them accordingly.

The Tang Police

Although named the Tang police it isn't just Tangs which they care about. It can be any fish from Marines to goldfish where aquarium size is all important. Bigger is better but it's never quite big enough.

This attitude is often beyond all reason. with unrealistic suggestions about tank size being made. Don't misunderstand me, I always advocate sensible stocking but the extremists who bully rather than help are a real nuisance and put off many new hobbyists with their tactics.

Native freshwater fish

As soon as you see a title of a forum post involving native freshwater fish for the aquarium you just know that someone is going to say "it is illegal to keep them".

Well unless the species is protected quite simply you can keep them.

Collecting them is another matter. Nature reserves are obviously a big no no. Almost every body of water is owned by someone in the UK and you may need permission to fish there. But almost every species can be bought quite legitimately. But keep in mind that most of these fish grow quite large and you most definitely are not allowed to release them in to the wild without a licence.

Native marine fish

As above but with the extra line about you can't keep those without a water cooler.

Rules and bylaws are set locally, some don't allow anything to be taken from a beach while others do little more than ban dogs, so check the local bylaws before doing anything, in most cases it is fine to go rock pooling and to keep any suitable finds for the aquarium provided you know how to care for them.

Coolers are only going to be required if you intend to keep some of the species which live in the shallow sea, say from 5 to 20 metres depth. True intertidal fish do not need a cooler for their aquarium.

Water changes

You can't change to much water in one go. This one leaves me wondering just how fish living in a river manage? Where a 100% change of water occurs every few seconds.

In actual fact it isn't the amount of water or the frequency of the changes which may adversely affect fish it is the change in water chemistry. If large scale water changes are made very frequently then the water going in to the tank and the water taken from the tank will be very similar and so this is the best scenario for the fish since it means that they'll be living in very clean water.

You can't use rain water in a fish tank - It's to polluted.

This one always makes me wonder. What does the poster think that wild fish live in? Once the water has hit the ground, any ground, there is no possible way that the water quality will improve.

Something's really shouldn't be done

So having said all this it would be easy to think it is ok to please yourself and ignore all advice, but that would be a mistake. There are lots of lessons out there which have been learned the hard way and which shouldn't be ignored.

Lack of research

The man at the shop said

Siamese fighters live in tiny polluted puddles

I just bought this fish - what is it?

My grandad kept four goldfish in a bowl and they were fine

I want something more advanced, I've kept fish for five years now and I've done tropicals so I want to move on to marines. I've heard marines are hardier so they shouldn't keep dying like my tropicals did.

Help save fish keeping

Help to cut down on the myths surrounding fish keeping. On fish keeping forums.

Do your own (real) research, don't take the word of a forum member simply passing on an opinion (usually one they have read rather than it being original) as fact.

Or can you?

"You can't do that". How many times do we see this written on a forum, usually about some old practice or using a different approach than the norm, and it seems to be getting more extreme all the time. Sometimes it is done by someone genuinely trying to be helpful, other times this might not be the case. Animal rights groups would love to see an end to fish keeping and use every opportunity to discredit the hobby or to make it more difficult. But more often than not it is done by a fellow fish keeper who see themselves as some kind of expert having learnt everything there is to know about the hobby after managing to keep some fish alive for a while and who don't need to check their answers because they know that they are right already. (Except in most cases they aren't). The need to be seen to be right seems far more important than actually being right to such individuals and as such they perform a big dis-service to fish keeping.