29 Gallon Tank Mystery snails color fading and won't seem to breed

[altwitch]

I finally found some magenta mystery snails about 6 months back and placed them in my 29 gallon planted tank. I had hoped they would breed but so far no luck even with 2" of space at the top of the tank. I've had success breeding golds in the past, though not in this particular tank. Now they've started to show signs of losing their vibrant color but otherwise seem healthy. My guess was nutrition as most likely so ramped that up, but there are 9 in the tank and not all show signs of the fading.

Tank Parameters
Temperature: 77-78 degrees with heater
pH: varies a bit but tends to hang around 7.7
Both GH and KH: 7 drops API or 125 ppm for both
Filtration: 1 x Dual sponge filter, cleaned regularly
Substrate: Aquasoil with a layer of pea gravel
Tank is open top so refill water every 2 days; 33% water change every 3 weeks
Stocking:
10 Rummynose tetras (consistently red heads)
2 Otocinclus catfish
1 Black Swordtail male (lone survivor)
1 Male betta (well fed and rather tranquil)
9 Magenta mysteries
Estimated 50 red ramshorns (culled regularly by selling mature specimens to LFS)
Plants:
Val
Bacopa
Ludwidgia Natanz
Alternathera Reineckii
Micro Chain Swords
Feeding:
1 x Algae wafer once per day
Small feedings 2x per day; 2 days flakes/1 day variety frozen foods
Snello added 1x per week on weekends (changed this about 2 months back)

No noted signs of aggression by anyone.

Thanks in advance for any help with the mystery (pun intended),
Altwitch

 

[BigManAquatics]

No breeding, they may be all male. Or something they don't like so they don't want babies to live there. Those are the main possibilities i can think of anyway

 

[Candace]

What are ammonia, nitrate, and nitrite levels? These can affect them as well and your tank is heavily stocked - 9 mystery snails can really upset a cycle with their large bioload and it looks like you’re feeding a lot as well. It’s usually best to feed every other day or every couple of days (However I do feed my baby mystery’s under 2 months old daily). I do know that sometimes the shells can change color based on the water source (what’s in it) and on top of that magenta’s do usually darken, mine also started at a very bright pinkish-red color and have slowly darkened a more to purplish-pink color.

 

[altwitch]

Testing showed Nitrate and Nitrite at 0 and Ammonia very close, maybe .1. We do feed frequently mostly to minimize aggression as they are community tanks but usually manage portion size.

 

[Candace]

Testing showed Nitrate and Nitrite at 0 and Ammonia very close, maybe .1. We do feed frequently mostly to minimize aggression as they are community tanks but usually manage portion size.

The Nitrates being at 0 can suggest that the tank either isn't cycled or had a cycle crash. As for feeding, fish do have very tiny stomachs so 3-4 flakes is enough to fill them up, the only reason they usually over eat or act like they're starving is because their instincts tell them that they don't know when the next time they are going to eat is. As long as you're managing the amount and not over feeding that shouldn't affect your tank, so the likely-hood is that they're all male or all female. Males are usually a bit smaller than females but the only way to know for sure is to look under the hood (I, quite honestly, cannot tell one from the other). The way to get them to come out of their shell enough to see is to hold them on their back, half in and half out of the water. This can take a while, if you have the patience and are able to take a picture as well someone may be able to help you sex your mystery snails.