had a few problems

hope everyone had a good new year! sorry this could be a long thread!

i went away for new year and i came back to a few problems.

15g - looked like my new male guppy brought 3 days before i went away had died Don't know why and had rotted in the tank. i only found a small bit of him left. the day i returned i lost one of my gourami, two days later the male gourami passed on. in that time i did two water changes one of 50% and a small one 10% after found the male gourami.
i've tested the water since ph 7 nitrates 5 others 0 so all fine.
i've since moved the female guppy back into my 40g. this leaves only 5 corys, who seem to hide all the time, why???

could i add 2 further corys and a small shoal of some tetra??

Problems with 40g - on returning from holiday i noticed my ram had a white fungus along the bottom of his dorsal fin. i increased the temp, to around 28-29C and the next day treated with a fin rot and fungus control.
later that day i found 3 dead rasbora no marks or fungus. i lowered the temperature back to 24.5C.
Any ideas why these could have died??
the next day the ram was on it's side and very pale hour later he was dead.

again i tested the water nitrates 10, ph 7, others 0.

this all happen last week and i've had no other deaths.
since the rasbora died the remaining shoal has stayed in the long grasses and are not as active, why??

i want to add some more rasbora, possible?? problem is can only buy them very small 1cm ish. would my angel (1.5 -2inches nose to tail) eat them and would the much larger rasbora i have accept the new fish.

40g
3 swordtails
1 guppy
1 angel
3 ottos
1 clown pleco
8 rasbora

15g
5 cory juilli

thanks shekoi.

i'm going to leave it for awhile before stocking.

now i just need ideas for stocking the 15g. what shoaling fish would be best. i've got rasbora and neons in other tanks so somthing different. i want ideas then i can look at the fish later to see if i like them.
could i add 2 corys plus a shoal without over stocking.

Could i get an apple snail in the 15g - how do feed etc?

and would adding more rasbora to my 40g be overstocked? and would small rasbora be ok with my angel and remaining rasbora?

cheers shekoi.

tkos - you saying 5 corys is all i can fit in my 15g total?? they are cory juilli.

i was hoping for a second shoaling fish.

ideas
rummynose
black widow
black/red phantoms
golden/cherry barbs.