When I get my 4' back from the repairer, I'm going to try 2cm of 50/50 peat/vermilulite covered with 2-3cm of filter sand. I may also put a bit of laterite in there too. Hopefully then I won't need to put fertilisers in the water - making it harder for the algae.
Well, I couldnt resist....nice pic of sand. I was able to define well sorted and angular clasts of 90% at most quartz. I would side on 85% to be safe Judging by the iron staining on some grains, I would say the black stuff is basalt (iron and magnesium) with some independant grains of white coloured, rounded clasts of feldspars-plagioclase (calcium + potassium?). Its worth the note that the soluble minerals are rounded in this pic...makes me excited to see the difference There are some other unknowns which have have assorted colours and is probably just filling used by the company to dilute quartz content and thus save $$$ All in all, a relatively safe mix with minimal alteration of water chemistry should be enjoyed by this sample. Good porosity and permeability of water and nutrient flow should be enjoyed by this sand with minimal compaction due to the "locking" effect of angular grains in contact with adjacent grains. Hope this helps
well so far vaccing cant be easier... just hover the hose end a few cm's from the surface, and up she goes...
as for compacting, I dont see how much more compact it can become (also, I have a few Kuhli loaches and some BN's to scoot around) thinking of getting some Cory's and if possible (and available) Malaysian Trumpet Snails as they are good substrate movers and dont eat plants.