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Very nice. Really like the rock shoals, DW has a very good eye. Using big rocks is smart. Once algae covers the rocks a bit they tend to disappear a bit, bigger rocks disappear less. Some things you might want to consider... It looks like there are some gaps in between rocks that could be filled with a little bit of mortar. I know the look you're going, you want natural not mortared rock wall, so you don't want to grout them all. But when they're underwater things change. Just like in natural gaps will fill with muck. And you won't be able to see these gaps as well even with no algae. Not a big deal but imo, better to fill with mortar. You can still leave deep gaps, but they can be filled a bit. At least as far as I can tell from the pictures. Not saying this is important at all. The cracking mortar isn't a big deal of course. For other readers... Reducing water in mortar reduces shrinkage. Like dry mashed potatoes. Two 1/2" coats would reduce shrinkage. Or doing small sections. Each section shrinks and then an adjacent section is done. The shrinkage crack would happen where it's thinnest, over the folds. You can fill the larger cracks, like say more than 1/16", if you liked. This is a good idea to lock it all down, but not super important. What is kind of important is to wait 3 or 4 weeks before filling with water. 4 weeks is best. You can wet it down right away, a little standing water would be OK. There is a lot of debate on whether keeping cement damp is needed. 30 years ago it was a requirement. Cement never stops curing and it does need some moisture. So to me, in summer, I do think it helps. And it's so easy being at the bottom of a pond. The 3 or 4 weeks are needed for the crystal structure to form enough to be fairly waterproof and to completely enclose the lime. If you add water too soon the lime can leach out and weaken the mortar a lot. People fear the lime leaching out and causing high pH and can be a small issue with uncured cement. But the weakening of the mortar is of more concern imo. Before filling the pond hose down everything. Mortar, rocks, liner, until there's a few inches of standing water. No reason to scrub anything or use anything other than water. Let that sit for 12 hours or longer. Pump out that water. Now you'd be ready to fill the pond. This wash down gets rid of dirt and mortar dust and gives any surface lime a chance to dissolve into the water. Some people might tell you to wash the mortar with acid to "remove the lime". An acid wash has the opposite effect. The surface of cement reacts with CO2 forming a kind of "rust" called calcite. The CO2 can be in the air or water. Calcite has a pH of about 7 and helps seal the cement beneath. An acid wash would dissolve the calcite leaving fresh brand new cement with a surface pH of 12. Formation of calcite is also why you don't want a lot of standing water during the cure. You want CO2 in the air getting to the cement.

I built the middle pond last August 2007...Fought green water all year..had a pond expert give me some of his opinions to clear it up..(too much full sun).so I decided to move it and help the natural filtration by adding a stream..(I thought up the stream idea through reading all the posts in here)..new pond the last picture took me about 40 hours to build...or should I say move...I didn't have any help..and really never asked for any LOL...just drank alot of beer in the process LOL....(added that for Horton)..the rocks came from Debarrs here locally..I have about 10 ton at a cost of around 300 dollars....my brother n law has access to a dump truck...he's a landscaper by trade...he just saw the stream pond for the first time the other day...he wants me to add more rocks to make more planting beds...I'll probably do that next spring....I think its around 3200-4000 gallons now...I have 7 koi..9 large comet goldfish...3 fantails...2 bluegill...and around 15 babies..and one bullfrog..plus numerous snails...I removed the predators from the 2nd pond and released them to the wild...(2 largemouth bass, 1 channel catfish)..I miss the predators but they were eating everything I bought LOL..I hope I answered all the questions......:-) Dave Here is a link that might be useful: My brother n law's business

Oops, actually that was the wrong pic. That's a close up of the filter and waterfall return. The filter is at the back, it's a 260 liter reservoir sitting in a lined "pit" with raised sides. The reservoir is partially sunk into the ground so I didn't need to make the sides of the pit too high, or use too much rockery to hide it. I wouldn't really call it a top pond, it's not that big... The "bridge" is just a home-made bench because there is no other way to access the filter and stuff without falling in - it goes right up to the hedge. The white thing in the middle of the filter reservoir is a right-angle pipe joint where the water from th epump is directed to the bottom of the filter - where it then upflows through all the pan scrubbers and fake alphagrog layers. A black right angle joint would have been better, but I couldn't find one. Never mind - in the top of the reservoir watercress is growing nicely (to eat nutrients before they can feed algae in the pond) and should hide the joint it eventually. You can see an aluminium tube sticking out of the joint, which is my home made venturi to make sure the filter bacteria get plenty of oxygen. The filtered water overflows the reservoir into the lined pit (which also has some barley straw decomposing nicely in it), then it flows into another reservoir with pickeral weed, golden sedge, marsh marigold and water forget-me-not growing in it... then it flows back into the pond via the shallow waterfall. Lots of "dwell time" in each reservoir section, and the water doesn't flow that fast, so suspended material settles out quite nicely. I couldn't use a fast flowing or high waterfall, because the noise of it at night in Summer would be enough to annoy the neighbours trying to sleep with their windows open. So far the filter has been working really well, the water is crystal clear, but the real test will be next Spring/Summer when the weather gets warm again and I'll see how well it controls algae blooms...