The key to algae is realising what it is that triggers it in the first place. Light is the greatest trigger. I have grown some fuzzy green algae in a jam jar of tap water using just sunlight. I have also grown GDA in RO water as well, although this did take longer, especially with the lack of sunlight we have had this year.
If I can grow it in RO water, I have to wonder what levels water column nutrients will need to be reduced to prevent algae growth totally.
We all have phosphates in our tanks to varying degrees and I, like several others on this forum actually add phosphates as part of a fertiliser regime for our planted tanks, to levels where it is a non limiting nutrient. Of course, if we are honest, we have all experienced algae at some time, and will do so in the future as well. So if we are getting outbreaks of algae, and adding phosphates to our tank, are the phosphates causing the algae? Well, we also add nitrates as well, which is also a very popular target for blame when algae appears.
Speaking from my own personal experiences and mistakes, I have caused algae on three occassions, but with help from reading a lot of info from Tom Barr`s website, I know what caused the outbreaks. The first case was BBA and staghorn algae, which appeared when a CO2 bottle had run low without me realising. Under the high light conditions I was running in the tank, limiting plant growth triggered algae growth very quickly. I don`t know what it is exactly about a mass of healthy plants that supresses the growth of algae, but it was the CO2 fluctuation that brought on the BBA and staghorn. I haven`t seen either type of algae since I sorted out the CO2.
The next case was also caused by unstable CO2 when I connected two tanks to one CO2 system using a T piece. It took a few days to regulate the CO2 to both tanks at the correct rate, due to the amounts to each tank drifting for some unknown reason. This resulted in a losing battle with rhizoclonium, which I eventually cleared using a three day black out.
The most recent outbreak, spirogyra, was caused by me rescaping my tank. Disturbing the substrate released adsorbed ammonia in to the water column. From what I understand, and I could be wrong, plants don`t use ammonia when it is at barely imperceptible levels, but the presence of ammonia is another strong algae trigger.
If you are running a heavily stocked tank, it could be that the fish are depriving your filter bacteria colony of O2, reducing their numbers by a given amount. Coupled with the ammonia from fish waste, it could be that a reduced filtering capacity is leaving small amounts ammonia in the water column, and thus triggering algae. Most test kits won`t be able to measure low levels of ammonia, and can be fairly inaccurate at the best of times.
Of course, I don`t know what fish stock levels you have, so I am just surmising, but you may need to look at what is triggering your algae.
The "brown goo" you had was probably diatoms, that use silica to build a shell. They are normally associated with new tanks where there is silica readily available, possibly from the substrate, and I have read that it could even leach from the tank glass when it is first filled. I am surprised your Otos didn`t rid your tank of this type.
If your current algae type is rhizoclonium, then keep hassling and removing it as much as possible. It`s hard to say what your next action should be without a picture to show how bad the algae is, but once I realised I was losing the fight, I carried out a three day black out that got rid of 95% of it (control algae by limiting light, not nutrients). The remainder of the rhizoclonium was constantly removed, with some new growth appearing, but after two weeks it was gone. It has never come back because I knew what caused it (unstable CO2), and remedied it.
Algae can be triggered by light, CO2 and ammonia. In terms of nutrients, its list of requirements is the same as plants. We all have the nutrients in our water column, but we don`t all have algae. Practically everything I have learnt, or indeed misinterpreted, has come from the Barr Report, or from Tom himself, but it has enabled me to understand what I am doing wrong and, more importantly, what to do to put things right.
The only sure fire way to prevent algae is to not put a light over a container with water in it.
Dave.
now on several of the (real) plant leaves I have long, green, hair like algae developing. It is very hard to rip from the leaves, it's easier just to cut the leaf off.
..............love this forum
/www.theplantedtank.co.uk/algae.htm
