Evaporation

[AnthonyRibis]

How often are you all adding water to your ponds during the summer months? I have been doing it a lot lately. I dont believe I have a leak or anything, i think it has more to do with the heat, direct sun light and more surface area with the new bog. Which is working amazingly!

 

[sissy]

heat and plants use a lot of water .My humidity has been high and no rain and lost 3 inch's in less than 3 days .I made a shade cover for half my pond just to help keep water from getting to hot

 

[Timothy]

We are experiencing an unusual amount of evaporation as well. In fact, a couple of weeks ago I was so concerned I started isolating different sections of or pond system looking for problem area's thinking we had a leak.
We are on a well and can't afford to just run a hose out to the pond to top it up. What I have done is put gutters and down spouts on my shop and carport with adapters to 1 1/4" hose and run the hoses to the pond if rain is forecast. The roof square footage is 1 1/2 times the pond/bog surface, so if we get one inch of rain we gain 2 1/2" in the pond.
I have the hose discharges on the bottom of the pond so theoretically the fresh rain water displaces the "heavy" water on the bottom. If there's more rain than what the pond can contain it simply overflows into the yard.
Obviously, this does nothing for the evaporation phenomenon, but it does go a long way to make up much needed water.

 

[mrsclem]

Doing a lot of water changes because of high temps. Was out of town for 3 days and came home to find my large koi hanging in waterfall. water temp 86- added 3 air stones and doing 1/5 water change.

 

[Mmathis]

Yep, heat is getting to us, too! As a general rule, I only add water when I do my partial water changes, though, and I rarely just top-off. But I can tell I'm losing some water to evaporation -- just not enough to worry about.

 

[Timothy]

Doing a lot of water changes because of high temps. Was out of town for 3 days and came home to find my large koi hanging in waterfall. water temp 86- added 3 air stones and doing 1/5 water change.

Sorry to hear of your koi.
I understand the water change potentially bringing the water temps down, but I'm curious......creating an "updraft" with the air stones, won't that tend to raise the "cool" water from the bottom and warm it on the surface allowing it to circulate and essentially warm the entire pond? I'm assuming here that the air temps are warmer than the water.

 

[AnthonyRibis]

We are experiencing an unusual amount of evaporation as well. In fact, a couple of weeks ago I was so concerned I started isolating different sections of or pond system looking for problem area's thinking we had a leak.
We are on a well and can't afford to just run a hose out to the pond to top it up. What I have done is put gutters and down spouts on my shop and carport with adapters to 1 1/4" hose and run the hoses to the pond if rain is forecast. The roof square footage is 1 1/2 times the pond/bog surface, so if we get one inch of rain we gain 2 1/2" in the pond.
I have the hose discharges on the bottom of the pond so theoretically the fresh rain water displaces the "heavy" water on the bottom. If there's more rain than what the pond can contain it simply overflows into the yard.
Obviously, this does nothing for the evaporation phenomenon, but it does go a long way to make up much needed water.

Nothing harmful that will come off the roofing into the pond? I have some 50 gallon drums i was going to make rain barrels out of.

 

[Mmathis]

@Timothy That question comes up every winter, except it's the opposite concern in that case.

I think the biggest concern when you're dealing with warm water is getting as much oxygen into the water as possible. Warm water doesn't hold as much dissolved O2 as cold water, so in the warmer months the fish don't have as much available to "breathe." That's why ANY movement at the surface -- which is where gas exchange takes place -- will increase the O2 level.

So it's really more about increasing the O2 level than about cooling the water -- but they do go hand-in-hand.

 

[sissy]

I have a well and use rain barrels and an underground tank to store water from my gutters problem is no rain means they are now empty and rain for 2 days now has been at 60% chance and all around us they got rain we got nothing .I get a lot of grit off my roof and have to clean out the rain barrels every couple of months and my roof is 11 years old and a gaf 30 year roof .At this point I can't see it lasting 30 years .I use pvc pipe off my one pump to keep water moving on top .I think it really helps

 

[Timothy]

Nothing harmful that will come off the roofing into the pond? I have some 50 gallon drums i was going to make rain barrels out of.

I've been using this system for three years and haven't experienced any problems to date. My rationale - (and perhaps faulty,) is this; The roof has been rained on for a lot of years, so it's "seasoned". The same rain that falls on the roof falls into the pond, I have to put a caveat in here; I'm just a hobbyist with a few dozen goldfish, nothing fancy, but I will say with some satisfaction that we haven't lost a fish to water problems yet. There are folks that will take issue with my assumptions, but the fish, frogs, tads, plants and helgramites have done well so I'm happy if they're happy. It's all natural.
I don't know what was in your barrels, but what they contained may decide if they're viable for water retention. How will the water get in the barrels? How will you transfer the water from the barrels to your pond? A 50 gallon drum full of water is heavy! Would you have to move them full?

 

[Timothy]

@Timothy That question comes up every winter, except it's the opposite concern in that case.

Exactly. That's why I only use a surface heater in the winter so I don't super cool the water...................

So it's really more about increasing the O2 level than about cooling the water -- but they do go hand-in-hand.

Gotcha! I wasn't thinking of the O2 . I have an aerator, but between the bog and the waterfall I don't use it very much. I seldom see the fish on the surface, they generally hang out pretty close to the middle depth.

 

[Timothy]

......................I use pvc pipe off my one pump to keep water moving on top .I think it really helps

I agree and do the same thing. I have an in-pond skimmer with a dedicated submersible pump. It draws water through the skimmer, then the return is directed to a length of 1 1/2" PVC that runs along the bottom of the pond with a 45 degree angle nozzle on the end directing the water to the surface keeping it slightly riled up for a few feet before it settles into a gentle current.

 

[addy1]

I have used roof water since we built the pond. One is galvanized, one is shingles. Great water exchange when we get a good rain. No issues with the pond inhabitants.

 

[addy1]

The waterfalls. Bog surface area keep plenty of o2 in the water

 

[teeemkay]

I've been adding water to the pond too. Seems like when the daily temperatures started getting up above 80-85 each day, the evaporation rate went up as well.

 

[addy1]

My weather station shows ET which is so far ET this year is 21.86 and rainfall is 20.97 .



Water cycle of the Earth's surface, showing the individual components of transpiration and evaporation that make up evapotranspiration. Other closely related processes shown are runoff and groundwater recharge.
Evapotranspiration (ET) is the sum of evaporation and plant transpiration from the Earth's land and ocean surface to the atmosphere. Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and waterbodies. Transpiration accounts for the movement of water within a plant and the subsequent loss of water as vapor through stomata in its leaves. Evapotranspiration is an important part of the water cycle. An element (such as a tree) that contributes to evapotranspiration can be called an evapotranspirator.[1]

 

[AnthonyRibis]

So if ET is higher than rainfall you will have more evaporation? I have pretty much doubled the amount of plants I had from last year and created more surface area with the new bog.

I guess my major concern is winter time. I run my falls through winter and this year will be the first with the bog. I dont know what to expect and I dont want to have to do many water adds in the dead of winter...

 

[Timothy]

I can only address the second part of your response, but I can share from experience.
During the winter we don't run anything except a surface heater that keeps a small area of pond surface open for gas exchange. We shut down the bog altogether and it froze solid with no ill effects on the plants in the spring and the entire bog is above ground level. (There is a vacuum break in the high point of the bog supply line to prevent the bog from siphoning back to the pond when the pump is stopped.) We do remove the pumps, and any piping that is at the air/water interface to prevent freeze damage. (I just tie a line around the pipe in question and let it sink.) My theory with these two things is the ice and snow that accumulates on the surface prevents any water from evaporating, and the earlier in the season the pond ice is covered in snow the better as it slows the ice thickness forming underneath with the snow acting as an insulator. Last winter the ice formed 14" thick in our 36" deep pond, yet everyone survived with no ill effects. We don't run anything but the heater.

 

[Meyer Jordan]

My weather station shows ET which is so far ET this year is 21.86 and rainfall is 20.97 .



Water cycle of the Earth's surface, showing the individual components of transpiration and evaporation that make up evapotranspiration. Other closely related processes shown are runoff and groundwater recharge.
Evapotranspiration (ET) is the sum of evaporation and plant transpiration from the Earth's land and ocean surface to the atmosphere. Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and waterbodies. Transpiration accounts for the movement of water within a plant and the subsequent loss of water as vapor through stomata in its leaves. Evapotranspiration is an important part of the water cycle. An element (such as a tree) that contributes to evapotranspiration can be called an evapotranspirator.[1]

Without knowing the exact coverage in sq/ft and what species of plants are involved and what percentage of the total sq/ft that each specie covers, there is no way to determine an accurate evapotranspiration rate as each plant transpires differently.
A calculated ET rate is typically lower than the prevailing Pan evaporation rate as the plants provide shade which reduces the evaporation portion of the ET.

 

[Dave 54]

So if ET is higher than rainfall you will have more evaporation? I have pretty much doubled the amount of plants I had from last year and created more surface area with the new bog.

I guess my major concern is winter time. I run my falls through winter and this year will be the first with the bog. I dont know what to expect and I dont want to have to do many water adds in the dead of winter...

One should not run your walls throughout the winter lest you super chill the pond , as to evaporation it is our lot during the summer all you can do is top the pond up from time to time .


Dave