Rescued Tank Having Issues

[skinbad]

Hi all, ive been reading these forums for the past 6 to 8 weeks, and have found some great pieces of advice and knowledge, and seen some lovely fish and great set ups.

I was recently (6 to 8 weeks ago) offered a complete set up with fish, that belonged to someone else, whom was doing a terrible job of keeping the tank. I was only told it was filthy dirty, and all the fish were dying of white spot. Obviously i agreed to take it on, presuming within weeks at most, i would be cleaning and cycling an empty tank, but miraculously the fish survived a 90% water change, filter clean, and full internal clean. I also removed everything from inside, decorations etc, which i binned. The gravel and water that the fish were in, and that remained in the tank, as well as decorations and plants, all were brown, and looked like they had been freshly acquired from the local river! The filter was blocked, and completely blocked with algae / faeces, and took over twenty minutes of running water to unclog the top outlets. Heater had burnt out also, but didnt realise this till just after. I lost one tetra that was dead amongst the old gravel, and one tiny (TINY) golden/bronze as yet unidentified tetra whilst cleaning re-setting the tank. I did a water test on the dirty water, and it was roughly GH 180+, KH 120+, PH 6.5-7.0, N02 80, N03 120.

Since then, water has been changed for roughly 50% since re establishing through gravel cleaning, filter has been rinsed twice, once under a tap before reading on here that was a bad move, a few fish have been added, along with live plants. Everything seems to be doing okay, water has jumped here and there in those few weeks, but has fallen in time. Overall, i thought everything was going okay, but after todays readings, and a danio dying, im in need of advice, as to whether im doing something wrong, if something is about to wipe out the fish, or if the water is all wrong? info below:

Tank size:48"x12"x14" - 132 ltr, 29 gal
Current readings:
pH:6.5-7.0
ammonia:
nitrite:0
nitrate:20-40
kH:60
gH:80
tank temp:28c

Fish Symptoms (include full description including lesion, color, location, fish behavior):
The fish actualy all seem fine, but one longfin zebra danio died today, it was being washed around the tank, its fins had been shortened considerably, and it had a grey / silver coating across its rear end, was still alive at this point, but unable to swim. Prior to this, the fish had bloated along with a couple of tetras, and i was thinking it could have been breeding in better water, but now not so sure.

Volume and Frequency of water changes: 30% 2 to 3 weeks

Chemical Additives or Media in your tank: carbon media

Tank inhabitants: Inherited fish:
2 plecos not sure if common or sailfins, 1 6", 1 4" roughly.
3 golden danios, 1 2" and aggressive
4 zebra danios, 2 longfins
7 red neon tetras
5 black neon tetras
1 bronze cory
2 golden / bronze coloured tetras, red stripe

Recent additions to your tank (living or decoration):
5 bunches of live plants
1 aquatic frog
1 betta
3 dalmation mollies

Casualties to date:
Aquatic frog died within 2 days, found washing around top of water
1 longfin danio as described above
2 tetras before tank fully re established

Exposure to chemicals: none known

Digital photo (include if possible):

 

[skinbad]

OK, maybe i wasnt very clear, my question and problem, is with the Nitrate being high, and nitrite being zero. How often should i gravel clean to flush nitrate, and would that be what killed the Danio?

 

[Kelly-Jo]

The majority of tanks have a reading of around 20ppm for nitrate. As for the casualties, some may have simply died due to the adverse water quality not because of your doing. It is also possible that the stress of the water changes etc caused them to become more susceptable to illness; however, you did the right thing in doing a large water change and more fish would have died if you hadn't. As for the 30% water change every 2-3 weeks, I believe you need to increase this amount quite a bit. For the next week or so, I'd suggest doing as big a water change as you can every 2-3 days. If you notice anymore silver/white coating on the fish then try to work out if you think it's whitespot or a fungal infection and medicate the whole tank accordingly.

 

[Athena]

Also, I would say you were a fair bit overstocked in the tank. As someone else mentioned, you should be doing more frequent water changes, especially if you have a high stock level in your tank. Try not to wash out that filter again for a while because where you cleaned it over-thoroughly before, you are basically doing a fish-in cycle now - and that's a lot of fish to contend with when your filter bacteria is not properly established yet. Plecs are messy fish, too. I'd also not recommend putting a Betta into that setup. It will no doubt end in tradegy. They fair better when they are in a tank of their own. Read up on the betta forum for more info.

Aquatic frogs should be kept in groups of 3+ and the water level of the aquarium needs to be lowered to allow the frogs to swim up for air - they are not great swimmers and if the water level is too high, they may reach halfway and then run out of steam and float back down. If after several attempts they are unable to get air, this can eventually kill them. Depends how old the frog is as to how well they swim. Younger frogs dont have the same muscle power as an older frog.

Another thing that kills off frogs in community tanks is lack of food. They need to be fed specific foods, with the foods being put directly where they are (e.g. with a turkey baster) otherwise they will starve as they are not as quick as fish as finding food and usually the fish will gobble it all up before the frogs get a chance. He may have been malnourished before you bought him, though.

You don't mention your ammonia levels - do you have a test for that? It's a really important one.

Your nitrates are fine - if you do at least weekly water changes you should be able to keep the levels to around 20ppm or less. Great to see 0 nitrites - if you can find out what your ammonia is and test all 3 weekly you will know if you're on track or not.

Regards, Athena

 

[skinbad]

Cheers guys, good to know i got parts right. I didnt really have the time to fully re-educate myself, and have been party to conflicting previous owner experience and advice. As i said originally, as nasty as it sounds, i was expecting most to die after the condition of the water that they were in, so i was very pleased 95%+ survived, until the Danio went down yesterday. The rest of the tank looks good, no other fish appear to have the coating or issues of any kind.

I will gladly change the water regularly, but as stated, the advice i received beforehand, ranged from cleaning and water changing every month, to every other day, 2-3 days for a week or two then every week sounds about right?

As for the frog, it was a young one, we were told in the pet shop to feed it dried bloodworm, but to just sprinkle them on the water, though the fish swarmed for them.

I dont like casualties of any kind, especially ones that could be avoided.

 

[Kelly-Jo]

Keep up the good work I'd go with every 2-3 days for water changes for the moment and if your ammonia and nitrite stay at 0 maybe decrease to once every 4-5 days

 

[Athena]

Hello again

I think the majority of us have started off our aquariums with lots of incorrect advice - but, thankfully, we're all becoming better the more research we do.

Yes, carry on with the water changes as you're doing now. Once your filter has re-cycled itself and the good bacteria is at a level that can cope with the waste being produced by your fish, you should notice that your water stats reach a happy status quo (weekly testing just before your water change will let you know how well things are doing).

Some aquariums only need a water change every fortnight if they are understocked (I have an aquarium slightly larger than yours (I think it's 170 litres) but I only have smallish fish in there (4 x 3" fish and 3 x 2" and 1 x 1.5"), so I can get away with fortnightly 30-50% water changes, although lately I've been doing 25% weekly as I was finding it quite tiring carrying bucketloads of water back and forth to the sink every fortnight! I think as you have so many fish in your tank, you might have to stick to weekly changes.

I think this is where a lot of differing advice comes into play. One person with a 4ft tank may say "Oh, just do a water change every 2 weeks", whereas another with the same tank will say "Do water changes every 3 days!" - it's not the size of the tank that determines the frequency and there are no set rules on this. The amount and volume of water changes is entirely dependent upon the circumstances of the individual aquarium set-up and feeding regime. It's for each of us to work out what maintenance routine best fits our aquarium, based on those things, to keep our water clean and our fish happy and healthy.

Sounds like you're finding your way and I'm sure your fish will do fine, although sometimes if a tank is overstocked or has incompatible species, there may be a few losses along the way.

If you have any more problems, just let us know on the forums and we'll try to help you again.

Best regards, Athena