snails/shrimp now with extra pep

[chesterthehero]

ive had a snail/shrimp tank set up for over a year now.. it started as a 10g then moved to a outdoor 60g but that came down a few months ago because i couldnt keep it warm enough.. i ended up neglecting the tank for a while (job change) and in the end everyone that was left alive moved into a 25g tall indoor tank....
usuially the tank is pretty mundane.. i love watching it but theres not usuially a whole lot going on.....

untill this morning...

just to see if anyone would like it i tossed in a small piece of pear (no one touched it) before i went to bed... when i woke up this morning the tank was going bonkers... i didnt think much of it.. the untouched pear was removed and 20% of the water was changed.. i just noticed that the tank is still going nuts... the shrimp are all over the place and swiming around a LOT.. the trumpet snails which usuially only come out of the sand for food are all over the glass... i know when the water/sand gets unhealthy the snails will go to the surface and my shrimp start dying...
the trumpets are just going everywhere.. they are all over all 4 sides of the tank..
is this "normal" or maybe one of those "yeah they do that sometimes" sorta things.... or possiably a sign of something wrong...


sorry for the bad pic.. my camera died so i had to use my laptop... if they are still doing this in the morning ill have a better/bigger pic

 

[Lupin]

What are the water parameters?

 

[chesterthehero]

i cant give you an exact number.. my gf does the water testing.. but her reply was "everything is normal".. i know she checked ammonia, ph, nitrate, nitrite.. im not waking her up to ask for exact numbers cuz im pretty sure she will kill me..
"normal" for that tank is ammonia-0 ph-7 nitrite-0 nitrate-15/20 (tap is 20) temp is 76/78

im wondering if i missed a feeding lastnight.. i droped in a few sinking algae wafers and a few crushed up food sticks... and a bit of duckweed (they dont eat it.. it just gives them something to cling to while they eat whatever floats) the snails for the most part are back on the sand/moving towards the sand.. the shrimp covering the algea wafers and hanging onto the duckweed eating the foodstick bits...

 

[Lupin]

Never tried pear but it appears to me they must have been confused by the scent. It can happen when you use a strongly aromatic food and then remove it and the inhabitants look for it around. I don't think there is anything wrong with your tank.

 

[chesterthehero]

im thinkin you are right...

i looked at the bits pieces of pear in the rest of my tanks... NONE of my fish touched the pear... NONE of the snails in any of the tanks touched it...