QUOTE(shortpants @ Jun 16 2009, 11:35 AM)
ok this is my history...
bought new aquarium together with new planted plants... 1st batch are bout 8 guppies; 8 shrimps inside... with filters and lights, without bubble blowers. filtered water from below, coming back inside from top.... (how to say this hope understood)... water with anti clorine...
» bubble blower, u mean air pump rite? your filter, is using a water pump, goes up to a box on top of the tank, and then it drops back the water to the tank? if it is, then it is over-head filter (some called it different).after bout nearly 2 weeks, looking at the empty aquarium, i bought another 30 tetras and 10 female guppies; all from jalan pasar. it was on friday
on saturday morning, i fed them and when outstation, came back on sunday nite, only left 3 guppies and 6 shrimps.
there was no trip in electricity, filter and lights were on and working. felt water a bit warm (dun have gauge that time)
» guppies, to me the more fancy they are, the more sensitive they will be. experienced with breeding them before i get into scaping and plants. my rough estimation here is, it might be ammonia spike. too much fishes dumped at one time and your plants and bacteria are not capable yet to remove the excess ammonia produced by them. But the actual reason might vary.so change water, lef bout 3 inch old water and the rest new, add wit anti clorine, a bit salt and plant nutrient... took out the glass cover which only having bout 50 cents size of hole.... after few days, the left guppies also died....
» 3 inches left? hmm, that's about 95% - 98% WC i guess? that's a lot actually. WC is good but too much at one time can caused stress to faunas. avoid doing this in the future. if there's really serious problem, just WC max to 70%. weekly maintenance just WC around 30%-40%. and once a month, do WC 50%-60% WC.
Too much WC > stress to faunas > vulnerable to parasites > death if uncured.thn i bought 5 black tetra to test water again... after 4 days surviving, add another 20 blue tetras. yesterday add another 10 tetras all still survive... also add 2 bubble blower and temp gauge... my temp now from 33c now become 31c without any fan or chiller. sometime i off lights during office hrs and open back around 7pm till morning.
its already bout 1 week ++, 1 blue tetra died on saturday, the rest still survive...
» now u already experienced yourself, adding fishes slowly to avoid ammonia spike and they can do better in your tank. Just remember do not overstocked your fishes as they also need space to swim around. you may google on what's the best math to calculate amount of fishes in certain size of tank. goldfish on the other hands, needs double the space at least than other fishes.i fed them 2x a day, around 7am & 7pm
generally from your explaination, what the most I can see the problem is your tank is not cycled yet and you already dumped a lot of faunas in there. dont worry, it happens lot of times to a newcomer aquarist. patience is the key. cycle your tank first before putting display fish. you may want to google on how to cycle a tank as it'll be quite an explaination to post up here in details.
for me personally, i use plants to see if my tank is ready to put display fish in it. let the plants properly roots first else some fishes/shrimps might pull them out back. by the time my plants properly rooted, then the tank i can say already cycled (usually takes about 3 weeks to a month). ottos and snails will be inserted in the 2nd week. SAE will be in the 3rd week. and then on 4th or 5th only yamato shrimp will be added (because they have the abillity to root up foreground plants when it's still not properly rooted). then a week after that only i might consider putting in my display fish.
ya, i know...i take too long to some people. but hey, at least i know none of my fish died once they're inside my tank. human patience can save lives of the innocents fishes (even tho i care more of my plants than my fishes

).
but all the above is just my way of doing things. some people that pro enuf knows how to speed up the cycling process. i do follow those way (matured filter media, mulm in the base, bacter balls, etc). but i prefer to be on the safe side

finally, a words of wisdom from the professionals and seniors that you can find all over the net and it;s very useful...
"take care of the water, and the water will take care of your fishes and plants"p/s: im still a newbie also. lot to learn still for me too.... we all just learnin together and share our experience with each other. that's what hobbyist do rite?

good luck bro with your tank.