George Farmer said:What do you think is causing it, Mark?
in all honesty, i'm not sure.George Farmer said:What do you think is causing it, Mark?
A surface skimmer or daily paper towel wipe or increased flow or increased water changes will remove it, and if you combine low-tech and water changes you don't get it at all.In fairly still ("lentic") waters, surface tension creates a stable environment for organisms and offers the best access to carbon dioxide and oxygen in the air. The density of living cells on the surface may be ten to a hundred times what it is in the water layers just beneath the surface slick. Many bacterial strains in this biologically-enriched surface layer carry photosynthetic pigments, though you might not notice cyanobacteria, for example, until they stain your paper towel blue-green. There are also true algae, diatoms, fungi and single-celled protozoans in these organically-enriched microlayers.
Well, I mean if you have a big plant and it's suffering then this plant will contribute to the problem, but don't blame it on the plant. Fix the real problem. I've had loads of crypts and don't have this problem, so it can't be due to crypts.NeilW said:This has been the bane of my tanks life too at the moment. Both Garuf's and migt's findings with crypts are true to me also.
OK, so have you considered the benefits to the tank of healthy crypts and what it is that you're giving up by ditching them? How about lowering the light intensity? How about experimenting with the nutrient levels?NeilW said:I believe my problem is still a lack of flow delivering CO2 so I'm going to try ditch the crypts as a solution and make it a completely moss tank to reduce CO2/nutrient demand.
It does lots of things but it only indirectly affects surface scum.tyrophagus said:I don't have a chemistry degree but I have to wonder what adding EI ferts + high levels of co2 to a tank do to the water chemistry.
Calcium Carbonate is the substance in your tap water that causes the water to be both high in Carbonate hardness (KH) as well as General Hardness (GH) from the Calcium. Calcium Carbonate is easily dissolved by acids, and in nature, dissolved CO2 in groundwater generates Carbonic acid which then dissolves the CaCO3 and that's how it gets into your tap water supply. Calcium Carbonate is otherwise known as Limestone, or Chalk. There are no relevant interactions of the nutrient salts with CaCO3, however one trick when taking a bath is to add Epsom Salts (MgSO4) to the bath water which helps to prevent soap scum. High CO2 concentration in the aquarium water means high Carbonic acid content which dissolves the CaCO3 and keeps it in solution. You're barking up the wrong tree if you think EI is responsible for surface scum, which is made of oils and other carbon products.tyrophagus said:I was once told that the scum on top of the bath water was mostly calcium carbonate.