# Rice Paddy Tank - Advice Wanted



## vloeien (Nov 16, 2020)

Hi Everyone, 

Inspired by a Takashi Amano aquarium (reference photo attached), I'd like to recreate an aquatic rice paddy ecosystem. This blog has inspired me to try El Natural/Walstad for the first time. Would really appreciate your thoughts on my plan, below:

--17 gallon tank (23.5" W, 12" L, 14" H)
--1" soil (see question below)
--One of the following gravel/sands at a depth of 1": Seachem Flourite Black sand, CaribSea Eco Complete, or round river gravel/pebbles (approx 4-6 mm) my local aquarium sells
--A carpet of Marsilea crenata (dwarf four leaf clover) with background of Eleocharis montevidensis (Hairgrass) and floating Riccia fluitans
--About 4-5 rocks, covering maybe 15% of the tank bottom
--Approx. 6 rice fish, 6 amano shrimp, 3 nerite snails
--24" 3100 lumen BeamsWork DA FSPEC freshwater LED (via Amazon)

I may use the Dry Start Method to grow the Marsilea carpet, by the way. 

Some questions:
--What readily available soil would you recommend? Located in NYC, I'm basically restricted to what's available at Home Depot/online. I bought MG Nature's Care Organic, but it's .15% nitrogen...I could get MG Raised Bed Soil (.09% nitrogen) on Amazon, but it's very overpriced there. 
--Among the three black gravels above, do you think any one is best--or recommend another in black/grey?
--Having skimmed EPA, I know that planting as many species of plants is best (allelopathy, etc.), however I'd like to stay as faithful to the original "rice paddy" concept as possible. Is it foolish to pursue an El Natural/Walstad with only these three plants? They all seem relatively low maintenance. From what I understand, Riccia and Eleocharis are found together growing naturally, and Marsilea is also a natural rice paddy plant. I read a post from @pineapple who grew Eleocharis and Marsilea together. 
--Will rocks disrupt soil fertility (e.g., anaerobic soils)?
--Do you recommend using a filter or power head? If so, can you recommend an affordable product?
--Are Malaysian Trumpet snails a must-have instead of/in addition to nerites? They sound so beneficial to soil fertility. How do you ensure they don't breed out of control?
--Any suggestions on how to jump start beneficial bacteria? I generally use API's Quick Start or a similar product with every water change. 
--My understanding is that rice fish prefer colder water (64-75 F) temps. I thought about using a nano tank heater I have, or none at all. With winter coming up, what do you think?

Any and all advice from you experts would be most welcome.

Thanks so much for your help--love this community!
-Harry


----------



## Greendot (Jun 3, 2012)

Hey there, I am also in nyc. I started my first walstad tank 4 weeks ago and have really good successes with hairgrass... Look up my photos. I just started a 2nd tank 6.5 gallon. I was recommended this soil (by one of the many nice mods over here) I ordered it from Amazon even though it is cheaper from Ace because I didn't want to go pick it up with the car.... I sifted it to get out as much wood chips and perlite as possible and I am very happy with results.

https://www.amazon.com/gp/product/B005IZ2SSE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://www.acehardware.com/departm...gardening/flower-and-plant-fertilizer/7265036

I have MTS and I do not mind them breeding like crazy to be honest. I like seeing snails all over. so can't help you there.


----------



## vloeien (Nov 16, 2020)

Thanks, Greendot, for passing along the soil rec! Will definitely be using this one. 

I guess I don't mind seeing snails all over either, and presumably the population would remain at a healthy number based on available food? I'll give them a try.


----------



## Greendot (Jun 3, 2012)

To be honest I love snails in there. I have a huge mystery snail who is beautiful then bladder, mts, and ramshorn. I got the ramshorn and bladder from this really nice guy in queens for a great price. They are pink. 

just as an example of the great work of snails... I recently got some free plants and it came from a tank with zero snails... a puffer tank. The plants had a lot of green algae on it. But a day after putting it in my tank the snails cleaned them up completely. 

People put it in their heads that snails are pests but they do excellent work and I find them essential and fun to watch

I think the fact that I also have a pothos and about 30-40% floating plants helps with no algea issues...


----------



## mistergreen (Mar 3, 2007)

I'm sure there's a homedpot or garden center you can go to to get a bag a soil.


----------



## FlatfishTanker1 (Mar 13, 2020)

Rocks are good. Just put them on the bottom first and put the soil around them. It's best not to set rocks on top of soil. That can cause anaerobic activity. You can put thin plastic or something down first to protect your glass if you want, but not necessary if you are careful.


----------



## vloeien (Nov 16, 2020)

That makes sense! Thanks, FlatfishTanker1. 

Greendot--Your love for snails is infectious. I'm going to experiment with a few in the new tank (maybe Nerites, Ramshorns, and Trumpets to start). I currently only have a big blue Mystery. She's very pretty and fast and fun to watch, but if I don't feed her boiled cucumbers she eat the plants. She also escaped twice and on the second occasion met my cat. She's not going in the new tank. I think I'll plant a big fishbowl for her and some cherry shrimp eventually.

I live in Queens; is the guy you bought it from on this blog?


----------



## Michael (Jul 20, 2010)

Welcome to APC! I'm looking forward to seeing photos of your tank. You have gotten good advice so far, I'll try to answer some of your other questions.

--What readily available soil would you recommend? Located in NYC, I'm basically restricted to what's available at Home Depot/online. I bought MG Nature's Care Organic, but it's .15% nitrogen...I could get MG Raised Bed Soil (.09% nitrogen) on Amazon, but it's very overpriced there.
_Generally we want a simple low fertility top soil, usually the least expensive option. If you can't find anything but high fertility soils, do a few soak and drain cycles first._

--Among the three black gravels above, do you think any one is best--or recommend another in black/grey?
_They will all work, pick the one you like the best._

--Having skimmed EPA, I know that planting as many species of plants is best (allelopathy, etc.), however I'd like to stay as faithful to the original "rice paddy" concept as possible. Is it foolish to pursue an El Natural/Walstad with only these three plants? They all seem relatively low maintenance. From what I understand, Riccia and Eleocharis are found together growing naturally, and Marsilea is also a natural rice paddy plant. I read a post from @pineapple who grew Eleocharis and Marsilea together.
_Yes, I think you can do it with those three species. At first you might put in some fast growing stem or floating plants to absorb any excess fertility from the soil, and take them out later as the tank matures._

--Will rocks disrupt soil fertility (e.g., anaerobic soils)?
_Good answer above._

--Do you recommend using a filter or power head? If so, can you recommend an affordable product?
_Some type of circulation helps. I use Aquaclear filters with just some mechanical media in them. If you just want circulation, you can use a small submersible fountain pump._

--Are Malaysian Trumpet snails a must-have instead of/in addition to nerites? They sound so beneficial to soil fertility. How do you ensure they don't breed out of control?
_No, but they help. If the population gets larger than you want, put a piece of boiled cucumber or squash in the tank and remove it when covered with snails._

--Any suggestions on how to jump start beneficial bacteria? I generally use API's Quick Start or a similar product with every water change.
_With soil and plenty of healthy plants you will have all the beneficial bacteria you need._

--My understanding is that rice fish prefer colder water (64-75 F) temps. I thought about using a nano tank heater I have, or none at all. With winter coming up, what do you think?
_I don't use heaters in any of my tanks with mixed species of "tropical" fish. How cold does it get at night in your house or apartment? In winter, our house thermostat is usually set at 68-70F at night and 72-73F during the day. Uncovered tanks stay at about 70-72F all the time. Your rice fish would be fine._


----------



## tiger15 (Apr 9, 2017)

You should include some rice paddy herb, Hygrophila Aromatica, in your scape. Here is what a rice paddy in Vietnam looks like. Rice paddy is aquatic tall grass without rock or driftwood, but with a few scattered herb.


----------



## vloeien (Nov 16, 2020)

Michael, that was so helpful. Thank you! I feel much more confident now with your advice.

Thanks for the tip, tiger15! Very happy to be learning more about rice paddy ecosystems.


----------



## mistergreen (Mar 3, 2007)

I wonder if you can find rice seeds to grow out and then transplant into your tank when it's big enough.


----------



## hoppycalif (Apr 7, 2005)

This seems obvious, but may not be: why can't you use the rice in a bag of rice to grow rice plants? If the rice hasn't been cooked or otherwise processed it should be "seeds".


----------



## mistergreen (Mar 3, 2007)

hoppycalif said:


> This seems obvious, but may not be: why can't you use the rice in a bag of rice to grow rice plants? If the rice hasn't been cooked or otherwise processed it should be "seeds".


The rice we eat is processed and dead I believe. You need to find ones with the husk still on.

*** Organic whole grain rice might work ****


----------



## Michael (Jul 20, 2010)

Rice takes insanely high light--remember it grows in the tropics in full sun.


----------



## hoppycalif (Apr 7, 2005)

How do rice farmers get the rice plants they poke into water covered soil? I would expect that they sow rice seeds, then pull them out and separate them into single plants to be poked into the underwater soil. So, do they save live seeds from year to year instead of buying seed every year? California has lots of rice farmers, but I have never seen how they do it.


----------



## mistergreen (Mar 3, 2007)

You germinate and grow them to a certain age in pots or dry land. Then you plant each plant into a flooded field.


----------



## davemonkey (Mar 29, 2008)

Planting style depends on culture. Along the Texas coast, and I suspect California (with possible exception of organic), farmers can drill the rice into a dry field (like any other grain), or fly it on (spread from airplane) to a wet field. Once it germinates, they begin to flood, but the water is more for weed control than for irrigation.


----------



## mistergreen (Mar 3, 2007)

davemonkey said:


> Planting style depends on culture. Along the Texas coast, and I suspect California (with possible exception of organic), farmers can drill the rice into a dry field (like any other grain), or fly it on (spread from airplane) to a wet field. Once it germinates, they begin to flood, but the water is more for weed control than for irrigation.


It depends on the variety of rice. Most variety grow better in flooded fields, in addition to being weed control. I remember reading the BGA that grows in the water help fix nitrogen in the soil for the rice to use as well.


----------



## vloeien (Nov 16, 2020)

In lieu of planting rice seeds (which would be really neat--next time!) I received in the mail the dwarf four leaf clover (Marsilea crenata) and hair grass (Eleocharis montevidensis) from a Long Island, NY vendor (although they shipped from Florida). I was told these plants were grown submerged. 

A couple questions:
1. Does anyone have any experience with crenata? This doesn't look like submersed-grown dwarf four leaf clover to me. It looks either like it was grown emersed or a different species. Any advice on how to plant it and whether the existing growth should be trimmed?
2. Both species were $6-7 per two bunches ($75 for everything pictured). Each bunch, especially of the clover, is very small, like 1/2" wide max. Seems expensive, no? Is this typical as far as commercial pricing goes?
3. The crenata is experiencing some yellowing/browning, perhaps because FedEx was delayed a couple days. Is this normal, or would you mention it to the vendor?


----------



## davemonkey (Mar 29, 2008)

The Marsilea looks like emergent growth, and that will eventually fade away, being replaced by the small submerged leaves you are thinking of. It's been many many years since I've bought that plant, and that was from a fellow hobbyist, so I can't comment on the pricing. 
Plant the individual nodes (each of those clumps will have several nodes, where the leaves are attached) as you are able, or plant as clumps. Either way, expect the emersed leaves to begin to die off.


----------



## vloeien (Nov 16, 2020)

Thank you, davemonkey! 

1.5 week update (see photos attached) with questions below: 

pH: 7.8
kH: 3 (have added 2 tablespoons coral to filter)
gH: 6 (soft tap water; will continue adding Seachem Equilibrium) 
Ammonia: generally .25ppm; today is 0
Nitrite: .25ppm
Nitrate: 0 - 5 ppm
Light: 12-14 hrs with siesta; reduced today to 10 hrs (see below)
Water changes: 25% 2-3x per week

--Noticed today hair algae growing on a rock and some clovers, especially ones that are melting. How would y'all suggest I deal with it? I've removed some of it by hand. Also reduced light to 10 hrs (with 5 hr siesta). Can I add Amanos with .25 ppm nitrites?

--Clover is showing new growth. Should I snip old growth? Seems like the hair algae is taking advantage of the melted bits. 

--Biofilm that looks like oil is growing on water surface. Removing some of it by hand daily with paper towels. Let me know what you think.

Thank you, all!


----------



## dwalstad (Apr 14, 2006)

I would stop adding SeaChem Equilibrium. You're going to poison the substrate with all the sulfates that it contains. (Sulfates that percolate into the soil layer will be converted to toxic H2S that will hinder and kill rooted plants.)

So that you don't have to keep adjusting the GH, reduce water changes for now to once a week. Right now you are dumping in excessive amounts of sulfates to compensate for all those water changes. See if the coral in the filter cannot get GH up.

What is the GH of your tapwater? If it's above GH 3, you may not have to do any adjustments with the small, non-competitive plants you have chosen. That's only true, though, if you are using naturally soft tapwater, not water that has been artificially softened by a household water softener. (These ion-exchangers add too much sodium to the water.)

That's good that you are removing biofilms. (In some ways, biofilm removal serves the purpose of a water change.)

You could _carefully_ trim off dead leaves that are covered with algae. Otherwise, I would leave the plants alone.

I never had much luck with Crenata. The pearl grass, Monte Carlo, and hairgrass seemed to do better for me.


----------



## vloeien (Nov 16, 2020)

Thank you so much for your advice, Ms. Walstad. I have thoroughly enjoyed reading your research. Your book and concepts inspired me to pursue this (my first) El Natural tank, which has been extremely rewarding.

My tap water is soft (GH = ~2). I live on the 4th floor of a largely original 1920's apartment building in NYC, so I'm assuming there isn't a water softener installed?

In addition to adding coral to the filter, I sprinkled coral (1 lb per 10 gal) between the soil and gravel.

I will report back on the Crenata. It seems to be doing well at the moment, growing small new leaves and occasionally sending runners.


----------



## jatcar95 (Oct 30, 2019)

I definitely had some issues in my first tank with Equilibrium and my substrate going anaerobic. Will NOT be using it again, at least with this kind of tank. My new tank I just followed the recipe in the book to raise GH and have had no issues  (my water is very soft, 0 GH from the tap)


----------



## vloeien (Nov 16, 2020)

Yikes! Glad I learned this early on. Have I done permanent damage already? Have dosed about 1-2 tea spoon 1-2x per week for the last couple weeks...


----------



## jatcar95 (Oct 30, 2019)

If you aren't experiencing symptoms of anaerobic substrate, it's probably fine. I was using it for months in mine, and it wasn't like there was any catastrophic failure, things just gradually deteriorated over time. I wouldn't worry about it too much, just find an alternate source for hardness.

Like Ms. Walstad noted, once you stop doing water changes, you don't need to keep increasing hardness. Those nutrients don't evaporate with the water, so you only need to replenish them with a water change (and I suppose plants will use them up over time). My hardness has been stable for ~2 months with no additions.


----------



## vloeien (Nov 16, 2020)

Thanks so much, jatcar95. Other than adding coral underneath the substrate and to the filter (have done both of these already), is there anything else you'd recommend to increase hardness?


----------



## mistergreen (Mar 3, 2007)

A bit of Sulfate isn't bad, plants need sulfate. You can add CaCl2 for calcium. MgSO4 or MgCl2 for magnesium.


----------



## vloeien (Nov 16, 2020)

Thanks mistergreen. 

Would putting crushed coral and eggshells in the filter provide a similar benefit? Should I be concerned about providing iron too?


----------



## mistergreen (Mar 3, 2007)

vloeien said:


> Thanks mistergreen.
> 
> Would putting crushed coral and eggshells in the filter provide a similar benefit? Should I be concerned about providing iron too?


Extra iron in a dirt tank is not needed. CaCO3 in the filter depends on your pH, below 7 is good, above 7 doesn't serve much calcium. It's not water soluble and need acidity to dissolve it. Adding it in the dirt might be good since the dirt is slightly acidic. It's easier to get CaCl2.


----------



## jatcar95 (Oct 30, 2019)

vloeien said:


> Thanks so much, jatcar95. Other than adding coral underneath the substrate and to the filter (have done both of these already), is there anything else you'd recommend to increase hardness?


I would highly suggest the recipe in Ecology of Planted Aquarium. It's page 87 in my edition. The ingredients are relatively easy to come by and pretty inexpensive, the tricky part is just doing the math to figure out how much to add. Someone, I can't remember who (maybe mistergreen?), also suggested this calculator, which worked well in tandem with the recipe to help me get the desired hardness: https://rotalabutterfly.com/nutrient-calculator.php


----------



## vloeien (Nov 16, 2020)

jatcar95 said:


> I would highly suggest the recipe in Ecology of Planted Aquarium. It's page 87 in my edition. The ingredients are relatively easy to come by and pretty inexpensive, the tricky part is just doing the math to figure out how much to add. Someone, I can't remember who (maybe mistergreen?), also suggested this calculator, which worked well in tandem with the recipe to help me get the desired hardness: https://rotalabutterfly.com/nutrient-calculator.php


Thanks! In my next tank, I think I'll just add minerals to the soil.


----------



## dwalstad (Apr 14, 2006)

Good idea. See my post today on "Softwater and Soil Liming"


----------

