OK, got this done.
It's just 3 17L plastic containers connected with pvc
pipe. The pvc
pipe is 3/4" and there are 2 connecting each container. The inlet bulkhead is 1" so this should provide more than enough flow to keep it from overflowing. The second set of pvc
pipes are lower than the first set, so water should flow easily from the first to the second to the third containers.
And, luckily it fits under my stand! While at the store, I measured the bottoms of the containers. Being stupid, I didn't notice they slant outwards going towards the top (duh!). Still fits though. But I will have to build a shelf inside the stand so I have places to put stuff. (always something to do!)
Now I just have to silicone around the pvc
pipes and do a water test. I am thinking I won't have any problems though.
Why couldn't I have done this first? It cost me $18.
Here is a view from the back, so water flow will be from right to left in this picture.