Way to high. I advice below 5. Or better zero. Why 0 ? Coz it gives "you" a margin of safety.
Guppies need and prefer a water that is the opposite of Clown loach's..... just sayin'
More live plants and less artificial deco would be better ;)
You should lower nitrates until they reach 5 and...
Hello :)
250 liters for 4 clown loaches that will reach 30 cm long (maybe even more) is way too small. It is high stress due to overcrowding probably emphasised if they live with tank mates.
Can you provide water parameters in numbers ? And pictures of your tank ...
As lead is a poisonous metal, "usually" is way too imprecise to me. In doubt remove any of them.
We also use "weight" to stabilise plants but made of terra cotta.
Hey there :)
From time to time mine go for a stroll.... they roam around for a while, while feeding then just stop for a few days. This may be the case so in a day he will be up and "running" again. I never lost my Nerite from their strolls.