Hey Reno --- Lava rock should make an excellent base for applying hypertufa or just about any cement based mixture. Cement relies on either a chemical bond ( as in liquid bonding agants...aka: "glue")...or a good mechanical bond. The porous lava rock should provide a very good mechanical bond. If you are going for a faux rock finish on a waterfall/pond, I would highly recommend using a modified conventional concrete or mortar mix rather than the 'Tufa. It will be as easy to work, but much stronger and less prone to water permeating the material. A healhty amount of latex admix is advisable. It will make the mix stronger, bond even better and far less permeable. A big issue if you live in a hard freeze zone. Good luck. It is a very do-able project, just continue doing a little homework before you invest a lot of time & money. And don't hesitate to conduct some small scale tests to see how a given mix works before you go whole hog. All my best, Tango88

bwalters, I am sorry but I don't make guesses until I have all the information I can get. So I will tell you what I would have a client do with your problems. I usually have the client make the observations as they are easy to make and but are made over a period of time. The first thing I would do is stand a ruler up in the pond so that the ruler is partially out of the water. This makes it very easy and accurate to measure the drop in the pond level. Then I would fill the pond full and record the measurement from the ruler. Then with everything running come back and record the water level and the time. These observations would be no sooner then 4 hours apart but not longer then 8 hours apart. When the water between two measurements doesn't drop then I would refill the pond and turn off the biofalls. Repeat the measurement process and repeat with the 55 gal filter off. These measurements will help pinpoint where the problem is. It will also tell if the leak is at a constant rate and how large an area the water is getting out. The first set of measurements will confirm that there still is a problem. The next two will help tell us what part of the system is the problem. The time between measurements will allow us to know how fast the leak is letting water out of the system and if it slows down when getting close to the leak point. Mike

Sandy This "wall" is a bit hard to describe . It has several main functions but the primary purpose was to provide vertical grow space for various types of epiphytes. It is also a heating,cooling ,as well as a self watering self feeding (maybe??) system. lol I'll just describe the layout method of only the "wall" because it takes a book to describe the whole thing.lol It is located on the north side of the shadehouse wall,attached to the house wall, made mostly of 'painted expanding foam. It is above and behind the 150 aquarium. It has various "pockets" as well as natural materials for holdfasts for various types of plants. It is made and painted to look like a "rock " wall. It is 7x10 feet at this point. Water is forced by a pump from the aquarium to the 5 foot level of the wall at a very low flow rate so it drips accross 7 feet of the wall. i call this a "seep" because it's too slow to be called a waterfall ??lol The water flows down the wall and collects in a 2x6 foot "marsh garden" from there it flows into the lily pool which is located outside the shadehouse in the yard. After being filtered it is returned to the aquarium. The main purpose of all this was to expand the various types of grow areas and integrate the systems into a single system. Go from full sun to full shade, submerged to very dry. The goal is to make a "rainforest" rather than a collection of hanging pots in a grow area. Provide a home for the fish, lizards, frogs and birds . Pix have not turned out well for several reasons besides the fact that I don't have a camera lol. None of the construction pix turned out at all and now the wall can't even be seen due to the plant growth. lol. 3 feet is as far as you can get from the aquarium due to terrestrial growth so can't even get all the tank in one pic.lol There is also shading , and reflections from the glass. i look at my pix and I get confused as to what it is lol. I can see that the whole area is WAAAYYY to small and I'm hoping to expand to 25x25 feet and gain some roof height at least a couple of feet. Hoovb Don't need to test to know that all these chemicals are present due to the fact the water is coming from cycled pond water. The question is what is too much ?? The water and marsh plants are no problem as you can't OD them but Epiphytes is a whole different story. So far have not added any fertilizer to the wall part but feel almost certain that it's too weak particularly with "trace" minerals". But maybe not a problem??? thanks gary

Area is 20x20