There are two effects of ripariums on the occupants of the water, that I can think of: one, is that there may be considerably less water in the tank with a riparium, so the capacity for fish is reduced. Another is that the water areas can be heavily shaded by the above water plants, making it difficult to grow some aquatic plants. The first effect can be reduced by growing the above water plants largely above the top of the tank, so the water level need only be a few inches below the top of the tank. And, since this lets the above water plants spread out more than if they were confined in the tank, it also reduces the shading of the water. But, when you do this, it looks much, much better if the tank is rimless.