Fish Deaths, Algae On Sand & Specie Identification

[stubedoo]

Hey,

We've recently put some fish into my 300litre tank, and I could do with some help.

1. Zebra Danio deaths:

After fishless cycling my tank for about 3 months, We finally put some fish in 11 days ago. I added 7 x Zebra Danios, 3 x Platys, 2 x Neon Rainbows & 4 x unidentified (see question 2). I've regularly tested the water since the fish have been in and the results are perfect (ammonia=0, nitrIte=0, nitrAte<20, pH=7.2, KH=2, temp=25.5C). Yet despite this I have had 3 out of the 7 danios die and another one not looking so good now either. The first one died after 5 days and had a red, almost like gash across his side. The second one died on day 6, he had been detached from the group looking very weak for about a day (no markings). The 3rd one died suddenly yesterday (day 10), we didn't notice any signs of distress with this one. Now today a 4th danio has a small red spot/marking either side of his fin, and we are worried he will be next to go.

Anyone ideas as to what is happening? This is our first fish tank, so we are a little unsure. Could we have a disease going through the tank?



2. Fish identification required:

As mentioned above we've forgotten the names of one of the fish species we bought, I would appreciate if someone could identify them from my poor pics below (the top pic is a truer reflection of their colour):

3. Green algae covering sand:

And finally... We have a problem with what I assume is algae covering the sand. This starting after a few months of the fishless cycling, and became a pain to try and keep under control. We thought once the cycle had ended and we stopped adding ammonia etc it might subside. It did seem to initially, but it is still really bad. Again, any ideas/advice would be greatly appreciated. (pics below again to try to illustrate)

 

[Underwurlde]

You put ALL those fish in, in one go???!?!?

You're kind of meant to build up your stocking levels.

Andy

 

[Craster]

1/2 stocking immediately at the end of qualifying week is usually recommended after a fishless cycle, and I'd say the numbers quoted above are half stocking or less for a 300l tank.

 

[Amunet]

To me, it doesn't sound like fully stocking the tank was the problem. It sounds like 1 or more of the fish brought something with it and infected the other fish.

Also the algae looks like it might be blue green algae. I'm not positive on that though. Can you pick it up in big clumps? We had a bad problem with BGA last year and it would cover the substrate like that is doing.
http/theplantedtank.co.uk/algae.htm
A site that lists different kinds of algae and ways to get rid of it.

 

[minxfishy]

After a fishless cycle its fine to stock fairly reasonably otherwise you will lose some of the bacteria you have been building up, so I dont think that was your problem, as mentioned some of the fish probably had something wrong with them from the LFS.

The fish are gold barbs btw.

 

[tom_os]

im sure you did but just to make sure, you did use dechlorinator?

 

[Bigpig]

that defo loosk like BGA very nasty stuff had a huge problem with it the past few weeks


From http/www.theplantedtank.co.uk/algae.htm

Description

This isn't a true algae, but a bacteria called cyanobacteria that is able to photosynthesise. Covers everything in a blue/green slimy mat. Easily peels off but grows back again very quickly. It can smell pretty foul. It is very commonly found in the substrate and especially along the front glass where is receives light.

Cause

Often caused by very low nitrates. It is fairly common to have it growing in the substrate against the front glass from where it can spread. Sometimes it appears with new setups that have had light and ammonia present at some point. Dirty substrates and filters may also bring it on. Poor water circulation is another possible cause.

Removal

A blackout is the best method for this. Clean out as much of the algae as you can and do a 30 to 50% water change. If your nitrates are low then add some potassium nitrate to get levels to 20ppm. Remove CO2 and add an airstone. Turn off lights and cover the whole tank so no light can enter. Leave it for 3 to 4 days. No peeking and no feeding - fish will be fine without food for this period. After 3 to 4 days remove the covers and do a 30 - 50% water change. Remove airstone and start CO2. You will need to dose nitrates to keep them dropping too low again. Make sure your substrate and filter doesn't become too clogged up with mulm and also make sure you have good water circulation around the whole tank.
Another option is to treat with Maracyn which is an anti-biotic. Seems to work well but may affect the biological filter. In the UK it is illegal to purchase Maracyn without first getting a prescription for it from a vet.
If the BGA is originating from the substrate place some dark tape on the glass to hide the substrate from direct light.

 

[stubedoo]

Thanks for all the help everyone!

First off... If this is some sort of illness brought via the LFS. Is there anything I can do to treat it to stop it spreading through all my fish? I'm a little concerned the Gold Barbs (thanks for the identification minxfishy) have developed some extra redness in recent days, although they are still zipping around with no problems. Can you buy treatment for such things?

Secondly thanks to Amunet & Bigpig for the algae identification. It looks and sounds like the right stuff, especially since it arrived when I was sticking lots and lots of ammonia into the water during the fishless cycle. The remedy sounds like a royal pain, especially with the fish problems at the moment I don't fancy not peeking into the tank for 3/4 days.

p.s. In answer to tom_os... valid question, but yes I have been using dechlorinator.

 

[Underwurlde]

Maracyn is 100% ok with filter bactera & works well to eradicate BGA, as does a 3 day black-out.... however it will return as the root cause is not being tackled.

Taping up the sides of the substrate using black electrical tape is very good advice & easy to do... BGA seems to 'originate' in the substrate.

BGA to me is indicitive of new tank setups - I kept on getting the stuff untill after 6 months after establishing my tank I stripped my tank down, cleaned it, completely replaced the substrate & went planted.... & since then no more effing BGA.

Andy

 

[Amunet]

We did a blackout in our tank when we got it (twice).
Not exactly sure why it hasn't come back since though but I'm glad for it heh.

You could try maracyn though. Since it's not supposed to be harmful to beneficial bacteria, you might be able to take care of 2 problems at once Sick fish and getting rid of the algae.

 

[Vorpal]

Many pet shops, and even some fish shops, do not treat fish well. They overstock, put fish together that aren't good tank mates, they don't modify water parameters beyond using dechlorinator, etc. Take a look at these things where you bought your fish, and if you aren't happy with it, take your business elsewhere. Otherwise, you can expect some of the fish to die, or come home ill.

Look instead for a specialist shop, a fish keeping/aquarium club, private sellers, etc.

 

[Cichlid4life]

this thread is from 2009

 

[Vorpal]

this thread is from 2009

Totally missed that. I get a weekly update in email, and clicked on one the threads (I thought it was this one, but maybe it was a 'similar threads' and didn't notice it was form 2009.