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easyrider003
06-01-2008, 18:03
I was wondering if anyone could tell me what exactly factors into how clear water is as far as visibility? I have several pond around my house. I know that the bottom of ponds are muddy and some of the lake have no other water flowing through it to keep a current going to help clear it up. I guess I am just wondering why lake water is so bad as opposed to spring water, except for the fact that spring like vortex have water flowing up from the bottom constantly. Hope my question is making some sense and not confussing anyone.

mitsuguy
06-01-2008, 18:32
the more water flow there is from a clean source, the clearer the viz will be...

with lots of water flow, any mud and muck is really washed away... we dive the Comal river in New Braunfels all the time, and viz is typically 15-20 feet... that being said, the lakes we dive in are lucky to have 6 feet of viz in the same geographic region... the Comal is spring fed, so the water is very clear to start, and because there is so much water flow, any mud and muck has been washed away after years and years of flow...

ReefHound
06-01-2008, 18:38
There are so many factors but I agree it's mostly about water flow. Every body of water I've seen with good viz seems to be characterized by constant flow of clean water. Another factor is the sediment density. A fine mud will take a long time to settle out once stirred up whereas a course texture will settle out quickly. Another is algae growth but again that's related to flow.

rawalker
06-01-2008, 19:29
Other factors can be algae blooms and other organizms growth

mitsuguy
06-01-2008, 20:02
Other factors can be algae blooms and other organizms growth

but water flow rate still takes care of that... :)

Geoff_T
06-01-2008, 20:18
Other factors can be algae blooms and other organizms growth

Along with water convection. stuff will be stirred up by the heating and cooling of the water this is usualy most aparant above the first thermocline. I don't know how much this plays in down here in TX but when I lived in New England this could be a big factor on many lakes during the summer.

longtailbda
06-02-2008, 04:27
Water flow helps clear the crap out. Spring water usually has very little or no large biological material in it. Most ponds are full of washed in debris leaves ect and once in, it has no place to go.

rawalker
06-02-2008, 14:04
Out here in Arizona we have reservoirs that are called lakes. The flow is controlled but spring run off is when they generally get filled. From there it is a matter or how much boat traffic the lake sees. The boats stir up the mess.

ChrisA
06-02-2008, 14:23
..Every body of water I've seen with good viz seems to be characterized by constant flow of clean water.

What about the Ocean? Yes there are some rivers flowing in but even the Amazon is a triveal flow compared to the Atlantic ocean.

I think you have to look at both biological activity and suspended sediment independently. Biological activity is driven by neutrients and sunlight, remove either of those and it goes away. Suspended sediments depend on the bottom type (mud, sand or rock) and water motion.

Just yearterday I was diving off the beach. Out on the reef we had decent vis because the bottom there is rock covered with marine life but close in to shore it is shallow and a sand bottom. There the surge (four to five feet) stired up the sand to make 2 to 3 feet of vis. Same water, same conditions only thing different was the bottom type

ReefHound
06-02-2008, 16:14
..Every body of water I've seen with good viz seems to be characterized by constant flow of clean water.

What about the Ocean? Yes there are some rivers flowing in but even the Amazon is a triveal flow compared to the Atlantic ocean.

I think you have to look at both biological activity and suspended sediment independently. Biological activity is driven by neutrients and sunlight, remove either of those and it goes away. Suspended sediments depend on the bottom type (mud, sand or rock) and water motion.

Just yearterday I was diving off the beach. Out on the reef we had decent vis because the bottom there is rock covered with marine life but close in to shore it is shallow and a sand bottom. There the surge (four to five feet) stired up the sand to make 2 to 3 feet of vis. Same water, same conditions only thing different was the bottom type

I'm not sure what you're saying. Are you agreeing or disagreeing with me? I mentioned in my first post that type of sediment is a factor.

When I say flow I don't just mean turbulence. You can stir up a **** tank all you want - it'll still be ****. I mean a fresh input of clear water causing constant turnover. In the ocean, that comes from the world's ocean currents. As you said, take away nutrients and sunlight and you lose the biological activity. Most of the ocean's water is below the light zone and the ocean is a relatively nutrient-deficient body of water.

texdiveguy
06-02-2008, 16:24
Good vis is way over rated anyways in my thinking!!