Betta died after adding new fish...(LONG)

[Lesmiz4]

Hello, I'm a lurker here and you guys give really good advice, I was wondering if you had any ideas.

I have a 33 gallon tank. It is fully cycled, with readings of:

Ammonia: 0
Nitrites: 0
Nitrates: High...80+
PH: 8.0 (this is consistant)

I know that the Nitrates are high...although I do change 5 gallons of water every week. I have an AquaClear 50 filter with the bio rock things, a long bubble bar etc...

I had in my tank for about 9 months successfully:
6 Danios
4 Neons
4 Sturbi Cory's
1 Betta

I had one Danio pass away last month, other than that nothing irregular has happened. Unfortunately I cycled the tank with the danios, so while I was sad, I didn't think anything was really amiss.

On Saturday, I added some more fish. I thought it was a lot to add to the tank at once, but the guy at the LFS said it was fine:

2 Dwarf Gouramis
2 Neons
3 Cherry Barbs

One of the new Neons suddenly developed a white spot on its back and died 24 hours later (last night). I took the other neon out and quarantined it this morning, thinking that they might have Neon Tetra Disease, but he looked fine tonight. Then I looked at the tank and saw that my Betta had passed away.

I'm thinking the following:

1. The Nitrates are too high and that caused the deaths.
2. My tank is a little overloaded now, and I need a larger filter.

Do you guys have any ideas?

Thanks so much!!! I miss George (my betta) he was such a sweetheart.

 

[jm1212]

i wouldnt change the filter, but get a second on to aid it, such as smaller AquaClear or an internal Whisper 10i
the nitrates may have killed the fish but the thing that you need to change is how much water you are taking out every week. most people reccomend 10-50%, and for your tank's conditions i would go with around 1/3, which would be 11 gallons

 

[phanmc]

A 5g water change for a 30g tank isn't enough even when done weekly, try increasing the water change to at least 25% of the water, though the more the better. Most importanly, get your nitrates down to below 40ppm.

Adding a large amount of fish can lead to a mini-cycle where your current bio filtration cannot handle the additional load and will need some time to build up. You may not need to get a bigger filter, just do frequent water changes until your ammonia and nitrite readings zero out. If you cannot get it to zero out after a couple of weeks, then you'll need either more bio media or a new filter.

 

[plah831]

ooh, I agree that water changes are needed here. 80 ppm nitrates is very high. I personally freak out if I see it at 15 ppm (and I ADD nitrates because I have live plants).

however, since your nitrates are so high, I'd suspect you're dealing with old tank syndrome. a sudden, large water change will stress the fish because they are used to dirty water. the solution is to do frequent small water changes (5-10% EVERYDAY for 2-3 weeks) until nitrates get under control. after that, at least 25% a week, as suggested, is minimum. i personally do 50% water changes twice a week on all my tanks (even more often if the fish are having problems) as bare minimum maintenance.

 

[jm1212]

and after you test your water and the nitrates are still that high, you might want to do a 50% or more water change (an easy one will be 2/3 (22 gallons) since your tank can easily be divided into thirds) on the month mark, and that will make the nitrate level drop, into a better level and more manageable for the weekly 1/3 water changes, and then the next month mark you do another 2/3 water change, and so on, until your nitrates are in a safe level

 

[Lesmiz4]

Thank you!

I just wanted to thank everyone for their advice.

I've been doing daily water changes now for 9 days, and the nitrates are now between 20 and 40. I bought myself a 50 ft. Python syphon and that helps A LOT. I can't believe the change in my fish...especially the danios. They are back to chasing each other all over the tank, and my corys are much more active than they were.

I'm trying not to make myself sick with guilt over the death of George (my betta) and the fact that I may have shortened the life spans of my other fish, but now I no better and I'll be doing 50% water changes regularly.

Thanks again!

 

[twig]

when considering how many fish to add consider how many fish you currently have. If you have 2 fish and you want to add two more you are effectively doubling the ammonia/nitrite output.

If you have six fish and you add a pair then it's only 1/3rd more demand on your system and thus you shouldn't worry about it too much.

Your nitrates are way too high. I don't know if its high enough to attack a fish but its much higher than my barely 5 nitrate. 25% waterchanges weekly will help. Plants also help keep nitrate down.

I think the tank could have been in a mini cycle.

 

[TKOS]

Sound slike you have things under control. In the future watch fish combinatipns as well. Gouramis and bettas generally do not mix and will fight. There is a chance the betta could have been killed.

 

[Lesmiz4]

I just learned that about the bettas and gouramis...I specifically asked this fish store (and this is a store that does ONLY fish...nothing else) if what I was thinking about getting was compatable with what I had and they said "absolutely!".

Next time I'm going to use my own judgement, not the LFS.

 

[TKOS]

Absolutely. It is great to find a fish store with knowledge, but ultimately it really is up to the onsummer to know what they are buying. Research is essential into your stocking choices. That is why it is always good to check out some websites and ask opinions online or in books. And multiple sources is always the best way to go.