I planted an elephant ear in pea gravel . It sat outside the pond (so it wasn't completely submerged) with water circulating through it into a waterfall . The leaves were ~5' long and the bulb was the size of a soccer ball by the end of summer .

Water celery is excellent for exporting nitrates but you have to keep it trimmed . Water hyacinth , Salvinia and Water Lettuce are even better but they're illegal to possess in Texas .

UV works well at killing algae and parasites . The only problem is that the dying algae rots and adds more pollution to the water .

Fish poop / urea ( and anything else rotting) breaks down to Ammonia . By scrubbing the pond down , you probably killed all the bacteria responsible for converting ammonia to nitrite/nitrate . It's a slow process . Try keeping a few pots full of gravel in the pond . When you decide to clean it out , put them in a bucket of aerated pond water .

When the pond is clean and the water is de-chlorinated put them back in . This will re-establish your bio-filtration .

I'm thinking this was the cause. So keep gravel in the pond and use it as the "activator" to get good bacteria in there again? Am I understanding that correct?

Should I only change a certain percentage of the water?

It was so green, I couldn't see 2" into the water.

I have two "ponds". The upper pond contains six red ear turtles from 6" - 10". If anyone has ever cared for turtles, you know the mess they are in an aquarium. The lower pond contains my goldfish/ minnows, etc. Between the two I have a "bog" or about a 100 gallon container that I only keep plants in. Essentially, it is a 100 gallon elephant ear root ball. There are mesh baskets in there but I just let them over grow it. I pump water from the lower pond to the upper pond and have two overflows- one into the bog from the upper pond and then the bog to the lower pond. (I use a 600 gph pump which is about 60 watts I think). I grow lily pads in the lower pond for shade. The upper pond is partially shaded and the turtles will just eat any plants- so nothing in there.

Maintenance involves trimming the bog regularly in the growing season and topping off with water. You shouldn't ever need to do water changes outside if this is done correctly. The waste and plant life should balance out each other. In the winter when the plants are dormant, I feed very little.

Man, I'd love to see some of ya'lls pond pics!!

Mine is rather small, but I will dig up a pic or 2.

Too many nutrients (nitrates) + sun = green water .

The bacteria that convert the fish poo (ammonia) to nitrate live on all surfaces (pond liner / gravel / plants /pumps /etc.). When you scrub down a pond or aquarium you're pretty much killing all the beneficial bacteria and starting from scratch .

I don't recommend "sterilizing" or using algaecides on a tank or pond . It's not necessary . Get some test strips from any local store like Walmart . Start out slowly . Ammonia means the cycle has started . Nitrite (extremely harmful-increase aeration) are the second step . Nitrates (plant food)are the final product .

When the ammonia/nitrite levels are high , cut down on feeding until you see nitrates . Keep an eye on the nitrate level . When it reaches ~ 50 ppm , start regular water changes of around 10% .

If nitrates keep going up , increase the amount of water you change or cut back on feeding / number of fish .

*Addendum* Always wanted to use that .

I keep several aquariums running . I take the gravel from one to start up a new tank so the bacteria are there to eat ammonia when I get new fish .

Oh I scrubbed it alright. Bathroom brush (new one) and power sprayer. I thought I needed to get rid of that or the green algae would come right back. That teaches me for thinking! DOH!

That sounds kick a$$ .
No probs with the turtles wandering to the other pond ? My bio-filter is a 100 gallon feed trough from Tractor Supply planted with Louisiana Iris . Didn't do a bog since the pump runs about 3000 gallons/hour .

I inserted a toilet flange in the side , slipped some liner over the flange and built a waterfall with flagstone . Works for me .

MY pond

The red ear are contained by a short wall around the pond- there is a basking area in the middle for them climb onto. This basking area is essential for long term care. My two oldest turtles are approaching 40 years now.

My turtle pond overflow is a shower drain w/screen mounted in the pond wall that drains into the bog via a PVC pipe. The bog container just overlaps the edge of the lower goldfish pond forming a small water fall.

I'm also a firm believer in having the "water fall" action within each container as it is the best no maintenance aeration mechanism and provides a small water current for circulation.

Get this....so I goofed and scrubbed the whole liner, pump, cut plants back (mainly fig ivy roots), and cleaned the hose. Fish died 3 days later.

Fast forward.....the water is green again. No plants, but there are tadpoles starting to show up. (Keep reading below for random thoughts.)

Is that crazy?


Okay here is a little thing I thought back too.....
I have dealt with fish kills like this every couple years. Fish get big and something happens. Well, the night all my fish died....3 pairs of toads had their pleasure night in the pond. I found them "hung over" looking confused the next morning. Pond was full of dead fish and the slimey string like frog eggs had been laid.

I remember years ago I had a fish kill the same night the frogs did the "dirty dance". Is there a correlation?

That is awesome. Love the deck to the waters edge.

I guess it's possible the love making created some sort of "bloom" which caused a spike in ammonia / nitrites. I would think for that to happen it would require a small pond volume and filtration that was just capable of sustaining only the fish.

I don't believe the tadpoles will be impacted much by the current water quality- however they do have gills before developing lungs so I guess it can't be completely ruled out.

As for the green water, if the surface catches full sun, I'd consider maybe some kind of temporary partial cover to eliminate light and some lily pads to compete with the algae for the available food- if you don't provide some kind of plants to remove the nitrates, mother nature will (algae).

Many a frogs are born in a tire's muddy tire tracks. They pump sucking them up might do more harm.

Odd thing...the outside cats won't touch the toads...but any other water frog is dead meat. (It ticks me off too...I liked the loud froggy nights!)