Since we use plant filters as our only means of filtration and water purification we are constantly searching for and testing plants that will thrive in our system. For those who subscribe to Tropical Fish Hobbyist magazine, I wrote an article about our system; please see “Plant Filtration—No Water Changes,” TFH April 2010.
When we originally developed the system we were in Santa Fe, New Mexico, where our well water came up at 53°F and being at 7,000 feet the climate is generally cold, so large water changes weren’t an option. In order to conserve warm water we implemented a recirculating system wherein all the water flowed through a large plant filter (10’ x 25’ and about 2 feet deep) before returning to the tanks. The plant filter was stocked with water hyacinth (Eichhoria crassipes), which is a floating plant that sends out horizontal stalks where new plant crowns grow. It is a very heavy user of nitrogen in the form of ammonia and it kept our ammonia levels at zero. Unfortunately, Texas, our current home, considers it an invasive exotic and has made it illegal to possess. Ever since we’ve been casting about for the perfect replacement.
We’ve tried red mangroves (Rhizophora mangle) and black mangrove (Avicennia germinans) and both have been successful in controlling ammonia and preventing the growth of single cell algae (green water) in our sun lit greenhouses. But we are always testing other plants. By accident I tested what has become our “Monster Plant.”
My mother had a small Dieffenbachia bowmannii (at least I think it is that species) that her cats had kept shredded and barely alive. I rescued it and placed it on the edge of the gutter in our cichlid greenhouse. Water from a nearby vat’s overflow splashed on to it so I didn’t need to remember to water it. After a few months it had grown into a very large multi-trunked plant about four feet tall. Also, I found that it managed to grow around and cut off a water valve. It’s roots had spread out into the water as well. It needed to be moved, so I chopped off the trunks and dropped each one between rows of 55 gallon vats.
Now, it’s important to realize this plant causes severe dermatitis when its sap comes into contact with bare skin. I definitely realized it that night when my arms itched intensely. Some cortisone cream fixed the itching.
Fast forward a few months. The damn plant was taking over.
The stems (actually trunks about 4 inches in diameter) were pushing the vats out of alignment, pushing pipes into our way, and clogging up overflows. Something had to be done. So, we are carefully removing the plant. (Ask Ashley, a hatchery technician, what happens when you aren’t careful; in her case a systemic reaction complete with hives everywhere.) In some ways it’s an ideal plant filter plant. It grows rapidly and uses up ammonia, but I think it would need to be placed in a large shallow tank where it could grow without interfering with operations. But, then how would you prune and cull it when it overgrew its container? At least with water hyacinth you could safely handle it and throw surplus plant into our Red Litter-worm beds.
Live and learn…
Peter Grothe says
Hello Goliad Farms and Mr. Clapsaddle,
I recently stumbled into Mr. Clapsaddle on YouTube through the aquariumcoop video tour. I really enjoyed the beautiful greenhouse design. I’d love to try a setup like Goliad in my small backyard. I’m thinking of design details like how the flooring is setup, what is the material, what is the water flow in the gutter and how do you measure that through floor angle? Is it better to start indoors or outdoors? I live in North Texas.
I really enjoyed the video. It’s like educational jazz the way you both riff plants and fish. Thanks.
Do you offer talks, courses, farm tours?
Charles Clapsaddle says
Our greenhouses have flat (zero floor angle) sand bottoms covered with pond liners (we call them “floor gutters”). Water stands about 4-6″ deep in the floor gutters. The sumps are about four feet deep and are lined with cinder blocks covered also with pond liners. In all cases we use aquaculture approved pond liners. The floor gutters have a lip formed by the cinder blocks at the sump edge. This keeps the water level in the floor gutters. The other three sides have higher lips to contain the water. As water enters the floor gutters, the level increases until water flows from the floor gutters into the sumps. Above ground pumps draw water from the sumps and return it the vats via 2″ PVC water lines. In each greenhouse, these pumps move about 40,000 gallons of water an hour, delivering about 100 gallons per hour to each vat. This maintains adequate aeration and, as a result, we’ve done away with blowers for aeration.
Since we are raising tropical fish and even in south Texas winter temperatures get too low, we have most of our vats in greenhouses where we can control temperature. Also, plant filtration is more effective if the plants don’t go dormant due to low temperatures in the winter.
I speak at aquarium clubs around the country 2-3 times a year. We have done farm tours for aquarium clubs, but we are still in recovery from Hurricane Harvey and aren’t really set up for tours at this time.
Jacob Johnston says
This is so inspiring! I recently started up my first aquarium and I’m hooked. It’s a 15 gallon and I only do water changes to harvest the water for other experiments since it’s better than tap. I’m a plant lover and the first thing I did was stick some cuttings in the water. When I finally started testing the water I discovered that ammonia, nitrites, and nitrates are always zero even though it’s overstocked and I feed generously.
I have some Tradescantia species in there, but the one I think could be relevant to an operation on your scale is Monstera Adansonii and/or Monstera Deliciosa (or various other Monstera species) although in my small tank I’ve only worked with Adansonii. I came into this article thinking maybe you, too, had stumbled upon Monstera as your “Monster Plant” lol…
Charles Clapsaddle says
Those are good recommendations. We are currently working with Pothos (house ivy), which in our greenhouses thinks its Monstera growing leaves up to sixteen inches.