Hi - Not sure what adverse comments you have heard about Akadama, I am using this without any problems and really like it. It does need rinsing well as can be a bit dusty, but other than that it is good. Although Akadama is good for absorbing nutrients from the water column, in my case I did use a base layer of JBL Aquabasis Plus containing additional nutrients, chose this as it is same colour as Akadama and if any mixing occurs e.g. when moving plants etc. it is not noticable and this has proved to be a good choice. However, if you are going to dose the water column this base layer is not necessary, I also dose the water column using dry salts, but just felt the Aquabasis would give the plants a better start and I think it did, plants are doing very well. Also Akadama, being clay based does not scratch the glass, but its consistency is good for planting. So I can recommend Akadama (Double Red Line type) and at about £9 a bag its not that expensive, with your size tank you might (just about!!) get away with 2 bags with a reasonable thickness, I have a 44" x 15" base and I used just over 2.5 bags!! Don't know much about JBL Mandano, did like the look of it, but read some adverse comments about this from shrimp keepers (cant quite remember now what the problem is with it) and as I wanted to keep a few shrimps I decided not to go for this. Hope this helps - Stuart
