Hi everyone,

Just a quick introduction, I have a 90L troipcal tank it is my first attempt at fishkeeping!

I had my tank cycling for about 4 weeks then got 6 black skirted tetras, 2 albino corys and 2 red clawed crabs. All settled nicely bar one tetra which I lost but it never looked right from the start.

2 weeks later I introduced 2 red honey gourami's and 2 peppered corys - this is when the fun started!

I noticed after about 2 weeks that one of my tetras fins looked funny it was like a white patch, I kept an eye and then one more tetra developed it. It looks exactly like cotton wool patches on them.

So I went to get some treatment and a test kit then decided it would probably be best to do a water change first and clean my filter. Did a 30 litre water change and then added the anti fungal treatment.

I'm worried i may have really upset my fish now as I bought a syphon got the water out very easily then realised I hadn't thought about putting it back in....I did it 10 litres at a time and just tipped it back in from the bucket and obviously the sand was disturbed at the bottom now the tank is looking cloudy!

Will this clear? Will my fish be traumatised by this? My 2 gourami's are swimming near the top now and because I've cleaned the filter even on the lowest setting its quite powerful so when they swin in the current they get pushed along into the wood or glass.
My corys also seem to be very still at the bottom which is most unlike them.

Any advice would be very much appreciated!

Thanks

Hi and welcome,

So we can try to help, can you answer these questions please:

What are your current test results for ammonia, nitrite, nitrate, pH and gH please?

When you say the tank was cycling for four weeks before adding fish, how did you cycle it?

Was this 30 litre water change the only one you've done since the fish went in?

It's worth noting that crabs don't make good companions for fish so you might want to reconsider them.

Hi Fishlady and thanks!

I bought an Interpet test kit and I must admit I didn't find it very easy tu use but I did my best! I think my PH was around 7-8, Amonia 1.2, Nitrate looked to be 100 mg/l and Nitrite 4.0 mg/l but like I said I found it really hard to read. it's one of those ones where you hold the viles up to the cardboard coloured values.

I was told at the fish shop that the crabs would be fine with my fish, I now know that not to be the case. I have been watching them closely and they seem to be keeping themselves to themselves in their desiganated corner I built them. They have wood leading up to a floating platform and quite happily sit up there for hours at a time.

Hi

OK, well it wouldn't be the first time shops had given poor advice unfortunately.

However, the immediate problem is that the tank isn't cycled. Cycling means building up a colony of beneficial bacteria to process fish waste from ammonia into nitrite and finally nitrates. Nitrates are removed by regular weekly water changes. The cycle doesn't start unless ammonia is added to the tank to feed the bacteria. In a fishless cycle we add liquid ammonia to grow the bacteria before adding fish and this takes about six weeks. If no ammonia is added, then the process of growing these bacteria won't start until fish are added to the tank and start producing waste. Unfortunately, that means the fish spend the first few weeks swimming in their own waste while enough bacteria grow to deal with it. That is called "fish-in cycling", and is what is happening in your tank.

The high nitrate level shows that so far nowhere near enough water changes have been done, even if the tank was cycled. When a tank is fully cycled 25% of the water should be changed every week to remove nitrates and to replenish essential minerals. When a tank is undergoing a fish-in cycle, as yours is, water changes need to be done daily to dilute the toxins (ammonia and nitrite) and protect the fish from their effects. Ammonia and nitrite should always be at 0 and nitrates below 40ppm in a fully cycled tank. Any reading above this is hazardous to the fish and will cause the symptoms you're seeing now.

Please read this article which explains how to deal with the problem effectively, and come back and ask if you have any questions.

Do consider returning the crabs as they are potentially a serious threat to your fish.

Thank for your help, I guess that is what I deserve for going to pets at home! I will be calling them to let them know that they're staff haven't got the first idea!

I just hope I don't lose all my fish now

I have a Maidenhead Aquatics near me. If i took a water sample in do you know if they would be able to test it and give me a more acurate reading of my levels?

I know that the liquid test kits are the best but I can't afford to buy one right this minute.

Would the 30 litre water change I did today be enough to shock the fish?

I have read the article and shall carry out all the water changes to get my tank sorted.

My main worry is that I can't rehome my fish temporarily and also I did clean out my filter today (in tank water) because it was running really slow and the red button was showing to tell me it needed cleaning.

I must admit I am disappointed that my fish are suffering I feel like I should give up and save the poor fish!

The daily water changes now should help alleviate some of these issues, for the first change aim for 40% (I'd only ever suggest this as an emergency issue) then 25% daily thereafter. Make sure you pre treat the water to deal with chlorine and chloramine and temp match to avoid shocking the fish.

Fish-in cycles can take weeks, so be a little prepared (think of all those calories you will burn off with them though) as you have to keep toxins low to avoid poorly fish. In fish-less cycles you don't have to worry about that of course.

Internal filters do need to be cleaned, usually weekly (50% of the media one week, the other 50% the week after) when a water change is performed or they clog in time. Always use old tank water, not tap water, or that kills off all the bacteria thet is growing and what you need.

Worth cleaning the impellor on the filter (the bit that spins round) evey few weeks too, toothbrush and cotton buds are good for this, as slime build up will cause it to
fail.

Crabs - mmm. Need to be returned asap. Crabs and fish, just as lobster/turtle and fish which we sometimes see here, is generally a big no no the fish in time simply become lunch I'm afraid! These critters need species only tanks.

Well since the water change and putting the medicine in I've lost my smallest albino cory and one of my crabs was on its back dying just a minute ago. I've picked the crab up and put him on his floating platform.

All my other corys are just sitting still at the bottom of the tank.

Think I may have sigle handedly wiped my tank out

I'm so, so sorry

The readings you indicated for the tank are really quite toxic though and many fish don't make it through this stage I'm afraid.

Is there no way of returning them or rehousing them possibly with someone you know with a cycled (so safe) tank?