Guppy fry dying after a few weeks?

Question

My guppy fry keep dying after about 3 weeks. I have tried different breeders (the current fry are in a breeder net) and I even bought a seperate tank to put them in (for the second batch) but they almost always start dying off after a few weeks. Some of them will get a strange bend in thier tail before they die as well. I am on my third batch of fry and they started dying off a few days ago, just a few dead each day... So far I have only had one who lived and he was the first one I ever had, he was the only baby of that batch that we were able to save. All of the adults are fine, it's just the fry that keep dying.

I clean the tank (about 20% water change) once a week and add Nitraban. I also test the water weekly, the only problem I have with water quality is the nitrates but I have been keeping them in the safe range. It is not a new tank set-up, however I have only been keeping Guppies for a few months.

The net breeder is in the same tank they were born in- with the adults. I feed them about 5 times a day with 3 different kinds of food (first bites, liquid fry food, and tropical fish flakes crushed up). I use a brine shrimp net to scoop out the waste from the bottom of the breeder net at least 2x a day.

Thanks for all the great ideas, I added aquarium salt earlier today after I cleaned the tank, and added pH decreaser as it was pretty high even for guppies. I will check out those web sites. The curvature only happens to the fry right before they die, I had thought of the vitamin or oxygen deficiency before, but I do have an aerator stone in the breeder net with them...
The overfeeding could be a possibility, I am trying to give them less food at each feeding.. Any ideas are greatly appreciated!

Answer 1

I can think of three causes for the curvature you describe.

One is a vitamin deficiency - similar to scoliosis. You may want to check the age of the food you're using or switch to another type (or provide a wide variety). Fry need to be fed well and often.

Another cause is fish TB - also called piscine tuberculosis - which is always fatal and can be transmitted to people. Until you can eliminate this possibility, use gloves when working in the tank (especially if you have any recent cuts).

The third cause is an internal parasite called camallanus. It's a thin, red worm that can be seen hanging out the vent when the fish is at rest. This can be treated (the entire tank, plus the parents' tank as well), but any curvature will be permanent. I'll put some info on these conditions below. I've also had the best luck treating camallanus with Levamisole HCl - something that's not listed in either site. You can get this through farm stores (it's a livestock dewormer) that's perfectly safe for use with fish. You can find directions for its use in aquaria by googling the name + fish or camallanus.

You may want to add a low concentration of salt to the tank water to reduce stress for the fish - about 1 tablespoon of salt to each 5 gallons of water.

Answer 2

It seems the fry aren't resilient to the possible water conditions of your tank. I had a situation similar to this. Bring a sample of the water to a pet store, they should do a test, but it seems the water might be the problem, also, don't overfeed (main cause of fish death). The water needs conditioning (aquasafe) is a brand. You can also purchase a cycle liquid. If the water smells like cat urine, you have too much ammonia in the water (also deadly to fish). Make sure you clean the tank as well, with all of these fish dying in the tank, waste and toxins are bound to build up, so do a 50% water change with an aquarium vaccuume (around 5.00)

If your tank is freshly set up, (started about 2 weeks ago), the water needs to develope a bacterial culture to fight other bacteria.

Answer 3

You probably are changing the water too often. Also, I use drinking water, and get a better survival rate with all my fish. I recently tried to separated a batch to put them in "cleaner" water and almost all died. It's just too much shock for them. For the first batch of fry, they all survived when I kept them in the same container the mom gave birth in, so the water was already conditioned. I would clean it by just sticking a turkey baster in there once every two weeks to suck out the waste.

Answer 4

since you have experience with adult guppies maybe you could help me

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