Water Changes
For most aquariums a water change of 30% once a week is just fine, you can do more if you want to, but we think it's better to sit back and enjoy your Discus.
A water change is really rather simple, take some out and replace it with fresh water - whilst doing this it is a good idea to give the filters a clean, wipe down the inside of the aquarium, remove any debris and waste product, trim any plants and generally give everything the once over.
You can add the new water "cold" so long as the temperature dose not drop by more than 3-C, if the water has been standing over night in a warm room you are un-likely to have to heat it - or if you use larger quantities, or need water quickly consider the "pre heated water" article.
It is prudent to monitor the pH and Nitrates in an established aquarium - if the pH crashes , this will be because of a lack of carbonates in the water, so either add some Bi-Carb (baking powder) or increase the percentage and frequency of your water changes. Feeding a lot of Beef-heart will drive the pH down, so be mindful of this.
Likewise "sky high " Nitrates indicate the biological filter is working well, but high Nitrates are not good for any fish and will induce algae in the aquarium, so again if you have high Nitrates (80 ppm and over) in the aquarium take action to reduce it - remember you will never get the Nitrate reading below that of your tap water, and for many of us that means starting @ 30ppm or more.
However if you want Nitrate free water for your water changes, with out resorting to RO or DI water, we offer a range of vessels to house Puralite Nitrate A50 resin Click here for the DD range of Nitrate removal products.