Well guys,
The battle against the brown diatomous algae is just about over, and dare I say it looks like it has been won. I have had to have a rethink on the plants and also take some pretty drastic action. Firstly I have removed practically all of the Eleocharis Hair grass, the original bunches I planted I have removed and just left the odd bit of new growth which is spread quite thinly reaching into the sand at the front of the tank. This doesn't seem to be affected and doesn't catch or accumulate any debris in the tank. I have replaced in parts the Eleocharis with Echinodorus Tennellus which seems to be doing really well.
The next thing to go was the Monte Carlos, it was just melting underneath and not rooting properly even though I was trimming it. I have also removed a few pieces of rock that were not adding anything to the look of the tank. I have removed these to make room for more plants and fill in the gaps in the substrate. This will help increase the bio mass and stop the Corys stirring up the Amazonia Soil.
Now comes the biggy. In the last seven days I have done three 50% water changes and one 80% water change. And here is the other shock news, I have not added any chemicals whatsoever. I have stopped adding the Easy Carbo and the Flourish Excel, and...stopped adding the EI Ferts in the form of Macro Nutrients or TMC + Micro nutrients.
Yes, thats right absolutely nothing apart from Co2. Why have I done this I can hear you asking. Well I was at the Green Machine last weekend having a chat with my mate Jim about the diatomous algae. After some long discussion and hard discussion, the advice was to do a complete Water Column Reboot, get the water completely back to its basic element of H20 with nothing added.
The thought process behind this was based on the Aquatic Triangle of Water, Light, and Nutrients. By a simple process of elimination we decided that there was nothing wrong with the water change regime, the water was going through a HMA filter and the filtration in the tank was sufficient, the Eheim PlantGro tubes and the Guisemann Aqua Flora Tubes are more than adequate to provide enough quality light for a planted tank. So there was just the final part of the triangle, the nutrients.
Jim knows I have been using EI Dosing methods and he knows if you get the balance right people are getting good results with it, so no real argument there. However Jim is a firm believer that if the balance isn't right, it can cause you all sort of problems. So between us we decided to do a trial, an experiment to prove one way or another what was causing my problems.
The reason for the high volume and high frequency water changes was to completely remove everything from the water column until the water was neutral, i.e. absolutely no Nitrates, phosphates, or trace of any kind whatsover. Each time I did the water change I tested the Nitrate, Nitrite and Ammonia levels. I always had zero ammonia and zero nitrite levels, but the phosphates and nitrates were always off the scale, so I kept doing the water changes until the tests came up bright yellow instead of dark orange bordering on dark red.
Once I got the water to this stage we agreed on doing a trial using half dose only of Tropica Balanced Fertiliser which basically means 25 ml once a week, adding some Sera Mineral salts and some Sera KH plus to buffer the PH and make sure the CO2 was being triggered. Keep the lighting period to 6 hours maximum with only one set of lights on for the first week.
It is early days but so far things are looking very good, the plants have started to pearl again, the discus fish are out a lot more and there is no sign of any diatomous algae, any that was still in the tank has died, the staurgyrene is showing signs of recovery and the altananthera reineckii mini is starting to flourish again.
So what was the problem? I don't think it is fair to say the blame lies solely with EI Dosing, I firmly believe that I got the dosing regime completely wrong, and most probably was not getting the mixture of the dry ferts in the right proportion, and then probably overdosing the tank. I know EI is supposed to be Estimative Index, but in my case I am sure I was putting a mixture in that was far too high in concentration.
So for the time being I am going to give this a month with the Tropica Fertiliser, standard large water change once a week and monitor the situation to see how it goes. I have not taken any photos yet, but I wll try and post some up at the end of each week so we can see for ourselves the difference it makes and monitor the results.
Cheers and thanks to everyone who has helped and given advice so far, even if I didn't always follow it
Steve.