well here are my results. i did a 50% water change yesterday but forgot to test the water first so i thought i would test it today.

nitrite 0 mg/l
nitrate 40 mg/l
amonia 0-0.2 mg/l
p.h 6.5-7

i know my nitrate are stupid high after just 24 hours of a 50% water change:(

i tested the water coming out of my taps today aswell and here are those results

nitrite 0 mg/l
nitrate 0-25 mg/l
p.h 7.5

i didnt test amonia as i didnt think i needed to:). a cant believe how high the ph was..

what actions should i take?

just incase you dont know here are my "specs"
tank 260 litre
7 inch oscar
3 inch oscar
12 inch pleco (he is for sale and hopefully going asap)
1 apple snail

standard internal filter and fluvel 404 external filter.

to begin with your tank is about 55 gallons or so. therefore you know that it should only have one oscar in it.(your overstocked) reducing the fish load will help in reducing your nitrates.

your ph isnt that high. oscars can tolerate a wide range of ph from 6-8 as long its stable it shoud be no problem at all.

you have enough filtratio for your tank so that should not be a concern.

you should test your tap water for ammonia. i have read that some people have had ammonia readings directly from the tap.

now the ammonia level should be at 0 so i would consider doing water changes every second day of about 25-30% until it reads zero.

i would also look at rehoming soome of your fish or look into a larger tank if you want to keep both your oscars

just my opinion

i know im over stocked thats why the pleco is going im just having trouble re-homing him. i will do the water changes and see how it goes, when i do one tomoro i will test the amonia in the tap water to.

does the snail make a big difference to my tank test results?

what would help the most. getting the 3 inch oscar out or the pleco?

Hi ricky. necromancer is right your over stocked and i would say rehome the plec 1st. dont try to do anything to your PH its ok how it is and will be better that way than you trying to keep it stable if you change it. my tap water is 20%ppm and this seems commom. with the right amount of fish to tank size 20% should not prove a problem. I have done all the overstocked,water changing bit myself and its noy easy. your life could be sweeter if you move some of the fish on. But its your call. you could try your local shop and see if they could help re home the plec for free.They will make a profit so are usely very helpfull:unsure:

erm..i dont want to give the pleco to my local shop as they dont have any tanks big enough for him. he is in the local paper next week and on a website so hopefully next week he will have a good hokme:)

i agree with marcus. rehome the plec first them you will have a bit of time to decide on the oscar or getting a bigger tank

quick update.

i did a 25-30% water change yesterday and tested the nitrate today

nitrate 35-40 mg/l

it has gone down but only a little but i supose it can only get better now hopefully:)

i put the new fileter in today and put my old media in it and the filter is so much more powerfull:)so this will defo help

nitrates can only be reduced by doing water changes. keep doing them every couple of days and eventually your nitrates will come down to an acceptable level. and keep the feeding down to a minimum this will also help

i will be doing another one tomoro...would you recomend doing one today as they are still high? if so what sort of %..stick with 25-30% of do a 50% or more?

i would do a 90% if i knew it would help my fish:)

personally i would do a big change today say about 50%. i know some dont like doing large water cahnges but i have done them many time to help in clearing silt from my tank when my oscars start digging in the sand. they tend to grab a mouthfull and swim to the top then spit it out so the cloud tends to stay for a while. after a day or two of diggin the floating particle really annoy me so i have been known to do 50% changes and nothing bad has happened to my fish.

ok, thanks.. i will do that now.