guppy fry always end up dying from clamped fins... NEED MAJOR HELP!

[caykuu]

1 year old guppy breeding failure talking here. My fry almost never survive. I thought guppies were supposed to be hardy?!

My fry always end up getting clamped tails and then die off.

They're in a cycled 5 gallon with a sponge filter air stone and a bundle of java moss. They've been living in the setup for about a week. I feed them simple powdered tetracolor flakes... bad experience with immediate clamped tails when I use brine shrimp flakes. Yesterday, I noticed 2 fry with clamped tails.
I just added in the sponge filter today, and then I noticed that more were getting clamped tails. So I did a 50% water change and added about a tablespoon of freshwater API salt (dissolved with water first, then added... of course), because I read on another forum that adding salt will help with clamped tails. Well, guess what? Now most of them are clamped.

My params are 0 ammonia, 0 nitrite, 0 nitrate. pH perfect 7.0

The fry are from 2 batches, ranging 2 months old to a few weeks to a day old, but their sizes are all pretty similar... because the oldest fry's growth were stunted.... but that's beside the point.

How how HOW do I successfully get my fry to survive the clamped tails plague and not have another mass genocide?! I don't want to get a tub of super medicine to cure, I just want to know what's CAUSING the problem and how to PREVENT it!
I feel like a guppy MASS MURDERER ever since I started the hobby.
If I made little graves for every fry, I would have dug 200 little holes in the past year. What am I doing wrong?! I must be cursed!

 

[maxwellag]

Do you mean their tails get torn or broken off? Sounds like someone in the tank is biting. Anything else in there other than guppy fry?

 

[Ponch]

One thing that read a bit unusual in the OP was that nitrates were at 0. In a fully cycled tank there should be some level of nitrates. Therefore I question whether the tank is truly cycled. How are you testing.... Test strips or liquid test kit?

There is a chance if you are using strips the test results are just wrong ( been known to be inaccurate) and if using liquid kit which is more accurate there maybe some very trace levels that sre able to still harm the young fry.

 

[warthog76za]

I find it strange that your cycled tank is still giving you fry deaths. Cause I have had my tank 1 and half years, Started out with 3 guppys and they tend to flourish in a balanced tank. Seems every few weeks I have more fry but I let nature take its course in the tank else it would be overrun with guppy fry.

Dont give up though, I know it can be frustrating, I went through a patch like this when I started out. Hope you get over this problem you have.

 

[Samzter]

One thing that read a bit unusual in the OP was that nitrates were at 0. In a fully cycled tank there should be some level of nitrates. Therefore I question whether the tank is truly cycled. How are you testing.... Test strips or liquid test kit?

There is a chance if you are using strips the test results are just wrong ( been known to be inaccurate) and if using liquid kit which is more accurate there maybe some very trace levels that sre able to still harm the young fry.

Not really. Some people, if lucky can actually get their water quality like that. Mine is the same. My tank is defiantly cycled because it had a old tank filter moved from the original tank into the current tank. It was running with another filter for a month until I removed it and added another filter. It just means you have good water quality.

 

[caykuu]

I have a pretty decent bunch of java moss in there, so I assume that's what's eating up the nitrates. I'm 100% sure my tank is cycled, and I use API test kits.

Their tails clamp up, as in.. the pectoral fin clenches together and become skinny; it's not torn or anything like that.

I woke up this morning to find all but 2 of the fry recovered from the clamped fins. Whew. But I still find it necessary to know the base cause of this issue, to prevent it completely in the future.

 

[maxwellag]

One thing that read a bit unusual in the OP was that nitrates were at 0. In a fully cycled tank there should be some level of nitrates. Therefore I question whether the tank is truly cycled. How are you testing.... Test strips or liquid test kit?

There is a chance if you are using strips the test results are just wrong ( been known to be inaccurate) and if using liquid kit which is more accurate there maybe some very trace levels that sre able to still harm the young fry.

Not if they just did a water change. I agree that test strips are inaccurate. The OP said that they have some java moss in their tank, so it is possible that it used the nitrates.

 

[caykuu]

I just did a 30% water change, and now a few more fry are clamped up again...
I use RO water with trace to heighten the pH to 7.0 to make it the same as the tank water.

 

[Biosfear]

I just did a 30% water change, and now a few more fry are clamped up again...
I use RO water with trace to heighten the pH to 7.0 to make it the same as the tank water.

If you use RO water exclusively you will need to add nutrients to the water.

 

[caykuu]

As I stated in my previous post, I use RO water with trace.