The next revision of my Turbo Algae Scrubbers will be finalized very soon. I still have Rev 2 parts in stock, but have decided that I will stop production of that version in favor of the new design. As of now, I have dubbed the Rev 3 the Turbo HF, which stands for High Flow. The Rev 3 will feature the following improvements: - Slot pipe is fully enclosed inside the box - Slot pipe will be easy to clean, inside and out - Slot pipe is indirectly connected to pump, so that the pump will not cause lifting or rotating of the slot pipe - Screen roughing process ensures plastic canvas is rough, deep into the screen - Dual-material lid is warp free (so far - long term testing still needed) - Lid will have built-in light blocker for slot pipe/screen junction - No more bulkheads - all box penetrations are tapped for threaded PVC - Larger side and bottom drains allow for very high flow, safely - New false bottom design more logically directs flow - New false bottom configuration allows for very high flow rate - Custom built 1" drain control valve for level control and drain silencing - Bubble blocker stops 100% of bubbles (more of an issue with high flow rates) So far, my "bench" testing of the L2 and L4 have shown that these units are capable of handling extremely high flow rates. I tested the L2 HF with a Mag 12 and measured the flow at over 650 GPH (across a 6.5" wide screen, that's 100 GPH per inch of screen width) with only a trickle of flow through the side drain (the L4 with Mag 12 tested 680 GPH and no flow through side drain). That is all with the small (1") drain option - you can go one size bigger, to a 1.25" drain, if you really wanted to. I did not have have a Mag 18 to use for that test! However, I will be testing a wider slot pipe to test some other high flow characteristics which may lead to a VHF model (Very High Flow)...or maybe UHF (Ultra High Flow) since no one uses those acronyms anymore!! Maybe Garf will come up with a better one. Who knows. The good news for all of you Rev 1 and Rev 2 owners is that there will be retrofit kits available for every one of the improvements on the list above. Final pricing is yet to be determined, but I will post that as soon as possible, probably before June 3rd. Contact me if you would like to be put on the list for additional information as it is available. I will not be making a "waiting list", rather an "interest" list. Once units are in production, they will ship on a first paid basis.