Help? Fish Dying Off!

[BlueDev]

Hello everyone. It's my first post, though I've been reading for a bit. It's been a crazy couple of days for my tank, as I've lost 8 fish in about 4 days, and for no apparent (to me) reason. Here's the basic information:


Tank size: 29 gallons
pH: 7.2
ammonia: 0
nitrite: 0
nitrate: 5-10
kH: Unknown
gH: Unknown
tank temp: 80F

Fish Symptoms (include full description including lesion, color, location, fish behavior): No apparent physical symptoms (other than being dead). Perhaps some increased aggression in general.

Volume and Frequency of water changes: 30% change at least once/week

Chemical Additives or Media in your tank: None

Tank inhabitants:
Here was the list before the massacre began:
4 Red Wag Mollies (2 adult, 2 large fry moved from fry tank)
1 Yellow Moon Platy
2 Dalmation Mollies
2 Dwarf Gourami
4 Lemon Tetra
4 Serpae Tetra
2 Siamese Algae Eaters
6 Neon Tetra
2 Snails
Some Hornwort

Recent additions to your tank (living or decoration):
The Neons and Snails were the latest addition, about a week ago. That's when things got ugly.

Exposure to chemicals: None


Once the Neons were added, I started losing fish. First it was one of the Neons, which I attributed to stress from the move to a new tank. However, a couple of days later, two of the Lemons were found dead (both with missing eyes, one with his belly gone). Then two more Neons disappeared. Then one of the Molly fry and another Lemon were found dead. Now a Siamese Algae Eater is missing (perhaps just hiding, but I can usually spot them).

I've noticed no obvious signs of sickness. About 6 weeks ago, I noticed some Ick spots on a couple of the Serpae. I added salt and raised the temperature to 86F, and it cleared up in a couple of days. I then did a few water changes and slowly lowered the temperature back to 80F.

When the Neons were first added, I didn't notice anything odd in the tank. After a couple of days, I noticed the fish were acting a little more aggressively, making runs at each other, but no nipping, and everyone's fins look fine. The Serpae have always been a bit aggressive toward one another, but they've never bothered any of the other fish. I moved around plants and rocks to break up territories a bit, and it seemed to calm down.

I've noticed no changes in the water chemistry, though I've been seeing a bit more algae than I'd like (which is why I added the snails). When vacuuming the gravel, the water has been a bit cloudy, so I've been doing water changes a little more frequently than normal.

The tank has been set up for a few months now--most of the fish were moved over from a smaller tank, because the mollies all decided to have a bunch of fry at once. I've never had a problem until this last week, and I'm stumped. Perhaps I'm missing something obvious--I could sure use any help, if anyone's got any ideas.

Thanks in advance for any help you may be able to offer.

 

[WILDER]

The neons did the red stripe area look bleached out.
When you do a water change do you preform a gravel vac.
Do the fish go pale or darker in colour.
Any fish acting listless and lethagic.
What do there gills look like.
Any excess mucas on the gills or body of the fish.

 

[BlueDev]

The neons (and all the other fish, actually) looked great. Colors were good and bright, and the fish were acting normal. Not acting lethargic or odd in any way. I haven't seen anything odd on any of the fish before their deaths--no mucus, no redness around the gills, no obvious color changes.

I do use a gravel vac when doing water changes.

 

[smegforbrains]

How big are the Algae Eaters? They can become aggressive & territorial when mature.

 

[BlueDev]

The algae eaters (now just one--found the other dead after posting) are small--other than the neons, they're the smallest fish in the tank. I had gotten smaller ones on purpose, as I heard that the larger ones could be more aggressive, and that the younger ones were more likely to actually eat algae. They've been shy and completely nonaggressive, so I don't believe them to be the culprits (especially with one now dead).

 

[Inchworm]

Hi BlueDev

It's possible that you introduced some kind of bacterial infection with your newest fish and snails. Sometimes they act quickly and don't show many symptoms.

I would suggest doing some additional water changes and reducing the temperature as much as possible with the fish you have. It might also be a good idea to add an airstone powered by a small air pump to increase the oxygen content of the water, and make sure that no uneaten food remains in the tank.

These measures will make the environment less hospitable for any harmful bacteria and will reduce the chances of the problem affecting your remaining fish.

 

[BlueDev]

The tank currently has an airstone, and the temp has been lowered.

I've also added some Stress Coat to the water and begun feeding with Jungle Labs medicated pellets.

Things haven't gotten better, though. Have now lost all of the Lemons, all of the Algae Eaters, and all but one of the Red Wag Platys and Neons.

The biggest change since medication has been that I'e noticed a new symptom. One of the platys started showing pop-eye last night and lethargy, shortly before he died. It's the first symptom I've seen, and I'm wondering if (a) the medication has slowed the disease, giving enough time to actually see a symptom before death, or (b) is actually causing the new symptom.

This morning, I noticed pop-eye on one of the gourami and one of the serpae. Frustrating!!!

Any more advice on what I might do?

 

[WILDER]

Are you treating with a bacterial med.

 

[BlueDev]

Are you treating with a bacterial med.

Yes, the medicated pellets are the bacterial type. I'm wondering if I should move to a water treatment instead of the food. I'm hesitant, as there still doesn't seem to be enough info to decide what type of treatment to use. At this rate, though, there's not much to lose by trying anything.

 

[WILDER]

Medicated food is good but it depends if the fish is till eating and getting enough.
Once you start to notice bacterial infections it can be to late.
If the fish is still eating keep going with the medicated food.
If fish are not eating better of adding a med to the water instead.