I had been having difficulty with my plants dwindling away, have tried using Marc Weiss Aquarium Vital and Flourish Excel with no real results. Our artesian tap water has 530tds, zero Iron and Magnesium, and a GH of around 1, ph 8.6. I RO/DI it as well, primarily to avoid the buildup of extremely adherant white dust/scale that builds up from evaporation on the tank lid. I have added a fertizlizer product called PMDD pre-mix (KNO3,K2SO4,MGSO4,CSM+B) over the past number of weeks, but saw no real improvement, so finally ordered a new stock of Sword, Cobomba, and Wysteria. The producer of the PMDD mix lectured me on not using Purigen, saying it was only for salt-water tanks, and that it would remove all the fertilizer and additives from the water. He said I need to decide what kind of tank I want, and that I should not add tannins and acid buffer either, as they do nothing positive for plants. My discus supplier tells me to please not add iron or hardeners to the tank. Can I not have a planted discus tank? I don't understand this.
Tech Support GL
04-22-2008, 11:47
Purigen can be used in freshwater, saltwater, and planted tanks. It adsorbs organic waste. It will not impact the other additives. Purigen can remove color bodies such as tannins from the water.
You can keep a planted discus tank and many people do, so do not get discouraged.
The water should be buffered ad it can be a carbonate based buffering system so the plants can benefit from the carbonates for growth and the pH can remain stable since you are using RO/Di water. You should use Acid and Alkaline Buffer together to maintain some buffering capacity and add carbonates. The plants will do well with a stable pH as well as the fish.
Discus do like soft water. Since you are using RO/DI water it is devoid of minerals meaning you can add some to the water and still maintain soft water conditions. 2-3 dH is soft water and can be achieved with to maintain plants and not harm the fish.
The plants you have are supposed to be pretty hardy. If they are dying within a couple of weeks more than likely it is not your water. With no iron the plants will begin to show some signs of deficiency.
There are test kits available to measure iron, nitrate, phosphate, hardness, and so you can maintain soft water with some minerals and nutrients for the plants while also maintaining proper conditions for the fish.
A good substrate base or adding Flourish tabs to the substrate can help with some of your dosing issues as well.