Read about Steve Stroupe

Title adapted from an American TV show, CSI, featuring a forensic investigative theme. First paragraph adapted from the introduction of the 1960s American TV show Dragnet.

Aquatic Plant CSI
by Steve Stroupe, Alabama USA
(also starring members of Victoria-Adventure's
email discussion list)

This is the pond. Somewhere in the Permian Basin in west Texas. I consult here. I carry a pair of Felco pruners. The name's Stroupe. The story you are about to see is true; only the names have been changed to protect the innocent.

Deep in the heart of Texas, unexplained plant deaths were occurring. The cause couldn’t be readily ascertained. Local experts were baffled, so it was time to call in the ad hoc team of international aquatic plant experts to solve the riddle -- Aquatic Plant Crime Scene Investigation.  

On behalf of the International Waterlily & Water Gardening Society [IWGS], I offer ongoing aquatic plant technical support to the Aquascape, Inc. network of Certified Aquascape Contractors [CAC]. This support is implemented through their internal message board and is usually a very easy gig. Aquatic plant culture, after all, is a fairly straightforward discipline with few surprises. Keeping aquatic plants alive and flourishing is well within the grasp of most anyone since most of the extant literature on this subject is dedicated to their eradication rather than their well-being ...

Last month however, things got a bit thorny. The Republic of Texas, which has an ego to match its square mileage ... just had to have a ‘Texas-sized’ problem with aquatic plants too ...

Michael Nickles, owner of Paradise Ponds, a pond design and build firm based in San Angelo, Texas USA (home of the International Waterlily Collection [IWC]) posted this question on the CAC message board on September 12:

Plants won’t grow in pond


Large Pond 300'x 100' x 6' avg depth
Multiple biofalls
Bottom aeration

System is 4 years old

Problem: Plants have failed to grow. Replanted multiple times with various species. The only thing that has survived are regular cattails (but they look weak and small) and a few waterlilies (bloom rarely and have extremely small pads)

Pond is filled and maintained by two wells

Water testing from a laboratory revealed the following:

pH when received 7.66
Bicarbonate as HCO2 185
Total hardness as CaCO3 3060
Calcium as Ca 536
Magnesium as Mg 418
Sodium and/or potassium 809
Sulfate as SO4 2637
Chloride as Cl 1364
Iron as Fe 0.69
Total solids, calculated 5949
Phosphate as PO4 20ppm
Nitrate as N 1.5
Nitrite as N 0.0
(results reported as milligrams per liter)

So Stroupe ... What say you?

Stroupe’s putative solutions were quickly exhausted with this response:

Plant CSI

Where is this pond?
Sun or shade?
Water depth [planting]? Lilies and marginals ...
Time of year planted?
Possibility of herbicide contaminants?
Test pH again with just a simple test kit. High pH is the single most common cause for this.
What about the soil the plants are potted in? Herbicide or other contaminant residue possible there? Have you used the same soil source each time?
Are you even using soil or are you planting directly in gravel for everything?

In the meantime I'll forward your test results over to someone smart to look them over to see if any red flags appear, and then we'll compare notes again ...

Mr. Nickels replied back quickly with this information;


Pond is located in Texas, zone 7

Full Sun except for a few perimeter trees
No herbicide contaminants
Bare root plants planted directly in gravel (as is every pond I have done with the same plants from the same vendor)

Will check the pH again.

Plants have been introduced in the spring, summer, and fall for three years with no success. Plants that normally "take over" any other pond will die in a matter of days if not one day. I watched ------ and water ------ die about 8 hours after introducing.

My perhaps overly-confidant reply based solely on the morbidity timeline of some of the deceased:

Plant CSI

The death of ------ and ------ is probably unrelated to the other plant deaths ... based on the info you've furnished. This sounds like they got overheated in transit which will cause them to crap out in a few hours after setting out, which is fairly common even outside of Texas. They were "dead men walking" when you got them I'm guessing.

We'll put them aside for now and concentrate on the waterlilies and marginals.

My expert has already passed this off to another expert, and I'm baffled, but we will throw this out to the entire international water gardening community if need be ...

Nothing like a good "whodunnit".

My “expert” was Jim Purcell, co-owner of Oregon Aquatics and a personal friend. He (much to my disappointment) demurred, and passed this question off to Randy McDonald of McDonald’s Aquatic Nursery in Los Angeles, California USA, who replied thusly to Jim:

Well, my thoughts on this, as I quickly review the information given, is like a doctor looking at the laboratory results of a blood test. I'm not used to such technical, chemical analysis of pond water because, normally problems such as these, are easily interpreted without all of this extra work, at least for me! In any case, the first thing that is a red flag for me is the fact that the relationship of calcium and magnesium is way out of whack. The ratio of magnesium to calcium cannot be any tighter than 3 to 1, calcium to magnesium and ideally 4 to 1. This water sample is very close to one to one which would definitely lead to dwarfing (stunting), and, or, contorted, deformed growth at best. Any good growth for any type of water plants, or even terrestrial plants with this ratio of calcium to magnesium would be a violation of everything that has been published in regard to this critical balance of these salts (ions when in solution).

The second thing that disturbs me about the pond is the bottom aeration. As I'm sure you know, cattails, lilies, and other true aquatics are adapted to and even prefer a bottom substrate that is not aerated, in fact, the more anaerobic conditions I give cattails and waterlilies, the better, faster, and stronger the growth. Just recently I tested this on viviparous leaf production of lilies. Tiny lilies that normally take a long time to develop under more aerobic conditions, developed and grew large in anaerobic conditions in a fraction of the usual time.

The third thing is that all of this filtration can only lead to a lack of ammonium for the nitrogen source for the plants' use. Everything in the way of nitrogen would only be available in the form of nitrates, something only terrestrial plants and algae like and use as their nitrogen source. So, another nail placed in the coffin of trying to get the plants to grow normally. Waterlilies and cattails prefer a backwater condition to grow normally. Most people in the trade know this as it is pretty well outlined in every book on the subject. The reasons aren't ever given in these books as to why this is true, which is baffling to me. It might help with the thought processes in the arrival to solving such problems as you are writing about. One fact remains after all is said and done. They like the backwaters, the sedimentary areas of deposition of both organic matter and colloidal particles, because that is where the anaerobic conditions occur, which lead to all of the chemical properties and bacterial interactions that they need, as dictated thru the millennium of time. This leads me to state my conclusion to the above information: "When in doubt to why a pond isn't working, in regards to growing plants, look and study a real pond." What they have created in this scenario is a pond that is perfect for the breeding and culture of fish, not plants.

At this point ... being way out of my normal operating bandwidth, I thought I’d present this problem to the 2000+ member Water Gardeners International/Victoria Adventure group online.

Chantal Piefer of Houston, Texas USA, responded to Randy’s second-hand post with these observations:

Very good point. In what part of Texas is this pond? Parts of Texas are highly alkaline, meaning plants go chlorotic and have limited access to the nutrients they need, especially iron uptake. Texas A&M in College Station is in one of the areas that is highly alkaline and I think they RO (reverse osmosis) their water for the greenhouses. Also well water tends to be much more mineralized -- could rainwater be collected to feed the pond? I can imagine that the evaporation they get and the constant topping off just increase hardness. Also what's the substrate of the pond -- if it's gravel, it should be something that doesn't contribute to hardness, etc. Limestone would be inappropriate. If it's concrete, there a general curing process (I'm not exactly familiar with it but vinegar or acid baths are involved) that helps to remove excess lime. If it's earthen, test the soil. Someone familiar with really controlling water conditions may be able to recommend a scheme for bringing pH and harness under control, but, at that volume, I can't imagine it would be cost effective.

Let us know how this goes. Good luck.

Then AJ Hicks, Chandler, Arizona USA had this to say;

If it were me, I'd haul a few buckets of the stuff off-site and put them side-by-side with buckets of plants grown in water from another source. If the prolific floating plants (water hyacinth and water lettuce) expire horribly at the CSI pond, then surely they would make for excellent experimental species.

You might also consult with agricultural or water quality people -- probably even the same ones who did the test. See if they think it's too salty to grow stuff.

Or, heck. What does it taste like?

From before:

Bicarbonate as HCO2 185
Total hardness as CaCO3 3060
Calcium as Ca 536
Magnesium as Mg 418
Sodium and/or potassium 809
Sulfate as SO4 2637
Chloride as Cl 1364
Iron as Fe 0.69
Total solids, calculated 5949
Phosphate as PO4 20ppm
Nitrate as N 1.5
Nitrite as N 0.0

So -- low nitrate and nitrite indicate it's not surface water, or there'd probably be a good slug of N -- more than 1.5 ppm combined anyway. Plus, the other dissolved components are more representative of saltwater intrusion. How far is this from the coast, and how much pumping are they doing locally?

Note that as a "secondary standard" (mainly for taste and appearance), sulfate is limited at 250 ppm:

Which puts the sulfate in the water sample in the "holy cow" bracket. Iron is more than twice the secondary standard. Chloride is more than five times the standard. Total dissolved solids are capped at 500 ppm, or about 1/12th that of the calculated quantity from the water sample.

Now that I look at it real hard and squint a bit -- yeah. It's saltwater intrusion. There's no other way to get such a spectrum of ions like that, in those strengths. The only other way would be some sort of drilling thing, i.e.: some drilling rig hit a salt dome and there was groundwater intrusion which has spilled over into the wells. Or maybe a hurricane storm surge or something like that, but it's some bad saltwater damage that's killing those plants. It's pretty obvious now that I look at those values again. The mix of values (versus "pure" sodium + chloride, because there's lots of
sulfate, lots of calcium, lots of magnesium) leads me to believe it's
from ocean water rather than a subterranean salt dome.

So- where do I send the bill for my consulting fee? :D

Not a geologist, but I play one o -- no, scratch that. I'm a geologist.


Now this is starting to get interesting as well as fun ... I’ve successfully diverted attention from my rather glaring inability to solve this problem, and have managed to successfully engage some real professionals in the process. I feel a bit like Huckleberry Finn whitewashing the fence...

An interesting observation came in from Cologne, [with water as hard as nails] Germany, from Jamie Vande who wrote:


Assuming the readings for ions is ppm, the Ca+ level is very high for fresh water. Marine water has 420ppm and is considered high. The pH is too high for many plants as most stop growing around 7.4. The readings for hardness cannot be correct! The level noted would be cement! There is certainly a decimal point of mismeasurement in there. Hardness is typically measured in dGH or ppm. Extremely hard water has a dGH of 30 and 530ppm.

Also, with the given Ca+ reading, the Mg+ reading is very weird. Mg+ is normally higher than Ca+.

In general, the readings given are suspect to me. Whatever they actually are, I believe the problem is the hardness and pH. Where did this water come from? Something has definitely contaminated it.

Hope this helps.

Jamie Vande
Cologne, Germany
town with water as hard as nails

This is really cool! People from all over the world are starting to contribute their expertise to help a Texas contractor solve his problem with dying pond plants ...

My response to AJ -- and I hope I’ve managed to reconstruct these responses in something relatively close to chronological order:

Thanks AJ...How could one determine if these combinations produced conditions which were too salty to support plant growth?

AJ’s reply:

Provided the plants are getting enough sunlight, I'd ask the following:

1) What's the water temperature? Is there any chance the well water is being pumped so fast the pond isn't getting warm enough?

2) What happens when pot plants are watered (and showered -- leaf exposure would be required) with the same water?

3) The water has too many ions in it. I'm thinking either it's too cold, or there's herbicide contamination. However, TDS is awful high. There may be another reactive species in there that doesn't come to mind immediately. Check with the local agricultural guys or the state water bureau, and see if there's something peculiar about that specific location. I mean -- combined sodium and potassium at 809 ppm is interesting, but -- heck, I'm sure some folks in Florida would have a chuckle at that level being a problem.

AJ almost sounds like “Columbo” (lead character in another American TV show) with that folksy, homespun, “aw shucks” demeanor, coupled with what is obviously a high degree of technical proficiency and a generous willingness to share it ...

Wishing to somehow remain engaged with all of these exceedingly intelligent and well-informed folks, I then offered the following supplemental information after a bit of research based on AJ’s theory and a further consult with Michael Nickles:

The pond (see photo) is located in west Texas in the heart of the Permian Basin. Potassium salts (potash) are mined from this area which is also dotted with oil and gas wells. The pond is approximately 75 miles due east of the southeastern corner of New Mexico and is quite a distance from the Gulf of Mexico.

All of the terrestrial landscape plants receive 90% of their water from overhead irrigation with water from this same well. According to the contractor, even salt-sensitive plants such as crepe myrtle show no adverse effects from the watering. The pond water will be retested shortly in order to compare results with the first test.

A similar pond less than half a mile away has flourishing aquatic plants with well water.

The floaters which deteriorated the same day they were placed in this pond were brought from a location two hours away under optimal conditions so they did not suffer from shipping trauma as I previously thought ... there was something in the water that effected their rapid deterioration within the same day.


Rich Sacher, hybridizer, water garden retailer, renaissance man, and Hurricane Katrina survivor had this to contribute, which he playfully titled, “Jumping In with Aerobics”:

This large Texas pond under discussion ... no one has said (or I missed it) if it is a natural bottom pond, concrete or liner. Sort of important to know. Also important ... are the plants in pots ... are they ever fertilized ... or, if planted in the pond bottom, is any supplemental fertilizer pushed in among their roots?

I have noticed over the years that some smaller liner ponds, when they have overly efficient biological filters, may be so devoid of dissolved nutrients that hyacinths, water cabbage and free floating anacharis will turn yellow and starve to death in the crystal clear water. And of course, in the case of the Texas pond, extremely high salt concentrations could tie up any soil nutrients which would otherwise be available.

I disagree, however, with the statement that waterlilies prefer anaerobic conditions. While there may be a wide range of tolerance for anaerobic soil conditions among various water plants, potted tropical waterlilies definitely prefer pots with holes in their sides and near the bottom, to allow water passage through the bottom root zone, thus providing aerobic conditions in the soil. Here is why I believe this:

When unpotting tropicals at the end of the season, from holeless pots only 10 inches (25 cm) deep, I would always find the bottom 3-4 inches (7-10 cm) of soil to be black, smelly and full of dead roots. The anaerobic conditions at the bottom of the pot eventually killed off the roots in that zone, and their slow rotting contributed to intensify the anaerobic condition. This would happen to every waterlily by the end of our season, every year, until I started perforating the pots.

If the pots are lightly perforated with even as few as 5-6 small slits near the bottom, the root system grows and thrives all the way to the bottom of the pot ... all through our eight month long growing season. The resultant growth of the waterlily is thus greatly enhanced throughout the entire season. These perforations allow passage of oxygenated water into and out of the root zone at the bottom of the pot, preventing anaerobic conditions.

The slits in my pots are only one inch (2.5 cm)long, and tight enough that no soil comes out. (I stab each pot a few times with a sharp steak knife!) Root systems of tropical waterlilies are so vigorous in perforated pots that, half way through the season, we often need to do a "chop and drop" on our display plants ... unpotting them, chopping off the bottom 3-4 inches (7-10 cm) of root ball, and dropping them back into the pot with more soil, so their crowns are once more even with the soil.

I do not doubt that some aquatics will do well growing deep into anaerobic Soil ... the lotus is one that comes to mind. But my belief is that the top few inches of soil in a pond (or in a pot) are able to have enough water exchange, along with the accompanying oxygen, that this top layer is fairly aerobic, rather than anaerobic. It has also become clear to me that by preventing anaerobic conditions in the growing pot, tropical waterlilies grow faster, larger, and later into the season.

Having now aired my observations...I hope y'all start perforating your pots.
Good aerobic exercise, if you have a few hundred to do!

Rich Sacher
Louisiana USA

Dan Robinson, Texas USA, added these questions: At one time did the pond support plant growth? What was the source of the EPDM liner? Not all EPDM "liners" are pond safe. Sometimes roofing liners are substituted and may have coatings that may be toxic to plants/fish.

Marian Ritchie, Texas USA, offered this comment: What about the gravel you used. Where did it come from and so forth? Do you ever fertilize the plants? I think the answer is going to be that something simple is out of whack. Sometimes we just over think everything! Good Luck and I hope you can solve this problem soon. Happy water gardening.

Dan Robinson weighed in again with this tongue-in-cheek solution: Forget growing plants. Bottle the water and sell it to aquarium shops as an algaecide.

Canadian pond professional Jeannie Suffern had this to say: On a general note, we have found in Alberta, [Canada] that aquatic plants do not do well in ponds filled with well water, especially if there is a high content of sodium, soda and sulphur. The hyacinths are usually the first plants to die off.

Aqualine Aquatics

Some further discussion was taking place simultaneously on the CAC Message Board.
A couple highlights from the message board:

From Cliff “Motel” McCready [don’t even ask]: Lots of good information here. My initial reaction was salt intrusion without even reviewing the lab analysis. AJ made the point very clear to me when he mentioned the high levels of sulfate, calcium, and magnesium (all found in salt contaminated wells). We had a pond in Foley, Alabama USA, (12 miles from the Gulf of Mexico) a few years back in which EVERY aquatic plant we installed died within a week with the exception of the cattails. (They were stunted also.)

What is the fish load like? I believe the only realistic solution for this large of a pond is to over load with "large" fish and monitor the nitrate levels and check salinity frequently during peak growing times (late spring and summer).

Also: How deep is the well??????

From B.J. Linger, CAC in New Jersey USA: Hey Mike, not that it helps ... but ... when I was there with you in the winter a couple of years ago ... I distinctly remember a white salt line on the rocks around the edges!

Jim Purcell of Oregon Aquatics finally commented privately with these insights which I felt presumptively free to share in this article:

Interesting. The consensus seems to be that there are too many mineral salts, and probably in the wrong proportions as well. Using the water to spray and water pots of terrestrial plants is a good idea; putting plants side by side in tubs using different waters is even better, but more work.

One thing I was thinking they should do is test the wells separately. If the water from one tests out a lot better than the other, they could perhaps use only one well.

If it is salt water and they can’t get rid of it, salt tolerant estuary type plants may be the best option. It is very limiting, but you deal the cards you are given. Maybe some mangrove species will grow there -- that would be cool.

Also, while it is possible that the ------ and ------ fried from overheating in transport, it is not a forgone conclusion by any means, and I would not rule out the water for them, either. If they were on their way out from shipping, there should have been some indication of that when the box was opened. As suggested, they would be perfect candidates for comparative water source studies, as they are easy to handle and react quickly.

Dennis and Luana Mitchell, Wailuku, Hawaii USA, had these questions to add to the mix too:

Hi Steve,

What an interesting situation. We've seen ponds similar to this here on Maui. Plants just don't grow. They don't die within 8 hours, but they never last more than a month.

Some questions:

1. Are there fish in this pond? Are they ok?
2. What is the dissolved oxygen?
3. Is there algae in the pond? What type(s)?
4. Has the pond been tested for copper levels?
5. This is a liner pond, correct?
6. Are you sure everyone is telling the truth? (There's always somebody in the mix who's not being completely forthcoming with the total truth.)
7. What trees surround the pond? They are not eucalyptus trees are they?

Somehow, and I don't know exactly what's going on chemically but these ponds can usually be improved with MASSIVE aeration. And oddly, it only needs it for 6 months to a year.

Keep us all posted!

Dennis and Luana

AJ Hicks again:

From this, I fall back on my bet-hedging consisting of this statement:

"The only other way would be some sort of drilling thing, i.e. some drilling rig hit a salt dome and there was groundwater intrusion which has spilled over into the wells."

I hail from natural gas country in western Pennsylvania, where the natural gas frequently comes "brine," a salty solution that must be captured and disposed of properly. The brine contains concentrations of heavy metals that are very nasty -- mainly strontium and barium, IIRC, but there are certainly others. These salts are left behind from the oceanic deposits which form the shale layers, which then undergo post-depositional changes that produce the hydrocarbons we value so highly, i.e. natural gas and oil. These products are pumped together (hydrocarbons + brine), the brine set side for reinjection into other wells that have usually been dead for many years, and the natural gas and oil then go on to make valuable products like shiny plastic junk.

If the brine is not captured, it ends up leaking into rivers and streams -- hardly quite so much of a problem in west Texas perhaps, but very serious in Pennsylvania. Some capture tanks leak, and the salt water (being salty) leads deer to feed on the water and salt crust that results, with predictable mortality -- usually to deer that are in utero. I seem to recall barium and (to a lesser degree) selenium are the problem species, although it's now going on 15 years; the memory is hazy, and Google is remarkably unhelpful.

With this in mind, a repeat water test -- along with a panel for heavy metals -- is recommended. Either the well has tapped into marginally saline waters, or there is some oil/gas drilling contamination or drainage or somesuch.

I would suggest the reason why the terrestrial plants are doing OK is that the exchange capacity of the soils is, for the time being, accommodating these element problems. If the area is desert dust-to-lawn, the surface soils are probably reasonably accepting of these ions, but their capacity will likely be met at some point. From there, they too may succumb. The pond plants, with a very low soil to water ratio, have met their match already.

While I am familiar with the area thanks to my time as a grad student in geology and geochemistry at New Mexico Tech (and as an occasional caver in southeast New Mexico which includes that spectacular Permian reef with similar geology to Midland), I have a friend who is a PhD in geochemistry who spends half of his time in Carlsbad. I'll bounce the problem off of him.


Dennis and Luana completed the thread discussion with these final thoughts:

Hi Steve,

Hmmm ... It'll be interesting to see what the heavy metals results are. I'm guessing there is copper in the water. Not enough to hurt the fish, but enough to kill the plants. Very strange indeed. And you're sure no one has used a chemical in the pond at some point? How about spraying around the pond? (We had someone spray Roundup on weeds surrounding his pond and it killed all his waterlilies.)

Our question about everyone being forthcoming with the truth was directed more towards the property owner/caretaker. Usually contractors are very open, but we've had some troubles with homeowners/caretakers NOT being so honest. For example: homeowner says -- "My pond is constantly green and smells. It must be all YOUR fault! You have to come out to my house and clean my pond for FREE!" We go out there and see that the homeowner failed to tell us they have a HUGE flock of ducks!

Best of luck! This is a tricky one. Just remember... usually the simplest answer is the correct one.

Dennis & Luana

After distilling all the advice from the folks at V-A with what we already knew, my recommendation to Michael was this:

OK ... after hearing all the ideas from some very informed folks, here are my recommendations:

A) Repeat the water tests and include salinity, heavy metals, and copper
B) Taste the water ... hey ... you're a CAC!
C) Forward the test results, assuming the new ones are consistent with the previous ones -- to the local extension agent and have him come out there if he will. This is a free resource so why not?

When we nail this down I'd like to post the results on the WGI/VA thread so everyone who helped us out can get closure as this is a rather unique situation.

Michael has agreed to follow these recommendations but we do not yet have the results of the retesting and additional tests. Kit and I thought it would be fun to let the WGI/V-A members review all the evidence ... then offer an opinion before the results are in. It’s also quite possible that the results of these final tests will not be conclusive, and we may not have definitive closure even then. Well that’s how real life is sometimes ... inconclusive.

Regardless of the ultimate outcome, this problem with aquatic plants in Texas simply serves to illustrate to what a wonderfully diverse and caring international pond community we all belong. It’s been a real pleasure participating in this exercise!

As soon as all the test results are in, they’ll be posted and published. In the meantime ... what do YOU think is the problem with this pond??

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