ianjones

im attempting to create an enclosed ecosystem in a 75gal that is as self-sustaining as possible. this is more of a science project than a pet display or aquascaping project. does anyone have experience with anything similar?

tantaMD

i think ur geatest challenge here is to create water movement without tech at all (including electricity)

mariannep

I think techiness and self-sustainance are separate issues. Real world systems get energy, from the sun, from the stream of water... If you want to go as lowtech as possible you'd have to attempt to recreate a system that matches your constraints. If you have no water movement you'll need to look at biotopes like seasonal ponds that's be similar. If you have no decent natural light, forget plants, etc.

I have in the past run tanks with only heaters and they did fine, better than many traditional aquariums, I'd say. Choosing different species could have done away with the heater, though I thought it provided some convection current, too. But perhaps some sun could manage the same.

Interesting project. Let us know how it comes along!

ianjones

techiness and self-sustainence are def separate issues with separate challenges...and im combining them lol. the tank has been up for a couple of weeks now. it is in front of a double-window, receiving direct morning thru midday Virginia sun and some indirect afternoon sun from across the room. Although the tank is no-tech, it does happen to be sitting in front of a heating unit and beside the AC unit, so regulating my house temperature does regulate the tank to some degree. the tank normally fluctuates between 70 and 77 degrees farenheit. the water in the tank has no chlorine, is currently at around 6.4 - 6.6 ph, stays around 75 gh (4.1 dh), but a big problem right now is that my water from the tap is at 0 kh ppm. though the water in the tank has recently risen to about 20-40 kh ppm, thats still a problem to me. however, i currently only have gravel substrate and possibly adding topsoil underneath could help? the tank has just finished its cycling (with help from a couple bottles of bacteria.) and is pretty well planted with whatever different species of aquatic plants i could find at stores, some emergent plants like water hyacinth and mondo grass, and im trying out some tropical houseplants as emergent plants, though im not certain they will grow (yet another experiment within an experimennt. yes...i always make things this difficult on myself lol). many of the aquatic plants are still alive, but havent grown much due to the nastiest onset of cyano ive ever dealt with. it carpeted the substrate and plants during the cycling, but has now cut back to being a more spiderwebby pattern and seems to dissolve a bit at night. green-spot algae has taken a big hold as well and is gaining ground on the upper reaches of the glass where the cyano isnt. im just being patient and trying to let things work themselves out a bit more at this point. the bioload is currently 10 snails (apple and trapdoor), 1 three spot gourami, 1 male betta, 3 female bettas, and 3 rosy red minnows (feeders). i generally use these species to start a tank, as they give me a constant feedback on some different water conditions before testing.

Skizhx

I gotta say, for every time I've seen someone using bacteria in a bottle products, very few of them seem to have what I would consider a smooth start-up.

Cyano in a new aquarium with little to no bioload would be a good example, and personally that sort of seems like one of those freaky problems you just wouldn't expect possible under normal circumstances...

But think about it... They're selling you aerobic bacteria sealed in an airtight container. This bacteria needs ammonia to sustain itself... So what are you actually buying by the time it reaches the shelf at the pet store? A bottle of dead bacteria floating in ammonia?

Anyways, enough about that (sorry :P)

Read Walstad's book if you haven't already. Many people have accomplished what you seem to be looking for.

You will need something to circulate the water in a tank that size, mostly to move and distribute nutrients dissolved in the water column, but make sure it's not disturbing the surface so you aren't releasing the CO2 that's being released by decomposition, respiration, etc...

Personally I don't use a heater, but I keep my place around 80 during the winters and don't have air conditioning for the summer. 70 seems a bit low. I would probably use a heater just for the fish's sake. You could probably get by without one, but why put the fish through less than ideal conditions just for the bragging rights to say there's no equipment involved IMO.

A nutrient rich substrate is essential. Unless you planned on dosing fertilizers or root tabs, regular gravel wont do much on its own.

You will have a hard time putting soil in a tank that's already established and running. It's much easier if you can remove the gravel to get the soil underneath it without any water in the tank. The soil I'm using currently, and my favourite so far, is Scott's Premium top soil with peat moss.

Got any pictures of the tank?

Good luck!

ianjones

skizhx,

i thought the same thing after i dumped an entire bottle of quick-start in (enough for like 240gal?) and it did a little of nothing! but i also used a dechlorinator prior to dumping it in and the dechlor said not to. oddest thing...my tap water, although it is town water, shows no sign of chlorine when i test, yet the levels in the tank were testing slightly dangerous, even though i used cold water at the start and made sure that any in the lines that may have run through the hot water heater was gone. ive been lucky enough never to have encountered chlorine in my tanks or tap before :/ the second bottle i used seemed to do a little better, although it can also be said that the tank was over a week into cycling. but the nitrogen cycle has leveled off now, and yet the cyano persists, so im going to figure out what else im doing wrong. im tending to think that the cyano is keeping the plants from growing and being able to compete for nutrients now that its established, plus i think that possibly because i have no nutrients in my substrate, the plants are receiving plenty of light but little else to be able to fight back against the cyano. im not overfeeding so the imbalance isnt due to phosphorus i wouldnt think. right now, im hoping that if i provide the plants ample nutrients to balance out the amount of light they are getting, that i will see a decrease in cyano and green-spot. so im going to get some topsoil today. i know its going to be a pain putting it in, but frustration is something i expected with this project.

i plan on looking for dianas book next time im in the fish store or somewhere that might have it. thankfully, th 70 degree mark only gets hit nominally. its mostly between 72 and 74. one of the things i pondered before i started was also maybe having (since there would be no water flow) a warm side and a cooler side. the water flow thing is something im gonna fight tooth and nail lol. putting some kind of powerhead, etc on there may make me abandon the project entirely. if ive got to run a filter with no media, then i might as well run a filter with media, and in that case ill just go back to keeping a normal fishtank without the hassle of keeping plants alive :/ how much would the movement of the fish carry the water do you think?

id love to have pics up to be able to say later "this is how ugly this project started. is there a place for a photo journal on here or do i have to put pics of my tank cycling up side by side with everyones completed aquascaping submissions? :P

ianjones

just added topsoil to my fishtank. the walstad method decrees that you put down 1" of topsoil, then 1"of gravel or sand, then place a saucer over the substrate and fill the tank up by pouring water onto the substrate as to not disturb it. forgoing her advice, ian jones' "hot mess" method decrees that you put the gravel down, fill a 75gal tank up with water, THEN put the topsoil under the gravel lmao

lets see the cyano live through THIS blackout! :P

Skizhx

Cyano is not true algae, it's bacteria, it tends to show up in neglected aquariums, which is why I find it odd that it showed up in yours so early. Personally I think the products you dumped were full of dead bacteria, probably some ammonia, and various toxic compounds released from all the dead bacteria which seems to me like it would be as good a cause as any.

Generally speaking, cyano likes low oxygen levels, stagnant water, and filth.

Water flow is more important in larger tanks (like yours). It has a lot of important roles from nutrient distribution to helping prevent anaerobic conditions, and aiding decomposition.

It wouldn't have to be a large pump or anything. You could hide it very easily. Personally I wouldn't scrap the whole plan over a $10 pump you'd never need to see or maintain.

The important thing to remember is to have no surface agitation.

Amazon carries Walstad's book.

http://www.aquaticplantcentral.com/f...degassing.html

Diana discusses water circulation in that thread. Might be worth a read.

Don't have any personal experience with a tank that size though.

ianjones

i also found it odd that the cyano would die back at night (when plants use oxygen) and come back a little during the day (when plants give off oxygen). but yeah. it could very well have been something from that first bottle. after the second bottle was added, the cyano died back a lot. it went from a carpet blanketing everything in the tank to mostly just a spider-webby looking mess. i was kinda hoping the green-spot algae would crowd it out, because as you said its not algae, its primordial nastiness and nothing i know of eats it (but for the case of spirulina) but i know tons of things that eat green-spot!

on a positive note, while i was pulling up all my plants to add the dirt i noticed that while many of the plants were just struggling to survive the cyano, the jungle val had actually sent off a runner and started another plant. yay!

corsair75

Most every 'bacteria in a bottle' product I've seen contains spores, not free swimming bacteria. They are very much alive, but generally take about 2-3 days to open up and start doing anything. The only exception is Bio-Spira, which claims to keep the bacteria in a 'hibernation' of sorts by keeping it refrigerated. "Instant" is a bit of a misnomer. Except for Bio-Spira (which many claim is bunk itself), all brands of bacteria have a 2-3 day wait time to start working. Now in a new tank, if there is no ammonia present, or no water movement to bring them nutrients the bacteria will die. In a freshwater environment there are precious few filter feeders to remove the excess. The cyano is most likely started off by feasting off the dead bacteria. Usually it doesn't show up in a new tank because usually it has precious little to consume at that stage.

As has been pointed out, "no-tech" doesn't necessarily mimic nature. Most systems in the wild receive some combination of light, heat, mechanical energy, and nutrients everyday. "Self sustaining" implies that you want the tank to feed itself too. That may be possible, though it would likely mean a minnow or two at most in that 75G consuming whatever microfauna you can produce. If you add food everyday, what is the difference (philosophically) between that and a water pump?

A tank is a semi-closed system. Basically, whatever goes in, minus what stays behind, is roughly equal to what comes out. In my 'natural' 55, I add light, heat, mechanical energy (pumps), nutrients (fish food), and harvest about a pound of leaves every week or two. Considering I add far less than a pound of fish food over that time, the other elements (like light) are being ultimately converted into live material. Input => Output. The size and level of energy running through that 'machine' determines the amount of life it can sustain and how well.

Think about nature. A stagnant pond of under 100 gallons, even in direct sun, usually hosts very little life. Algae, mosquito larvae, and bacteria. Even then, the insects bring in outside food supplies, and the bacteria and algae consume the remains of whatever is swept into the pool by rain. You don't see top predators like fish in such a small space unless it is somehow connected to a larger system. Fwiw, if the goal is really "no-tech," you may want to look to saltwater. The environment is much more rich with microfauna, and you might be able to get enough links in your food chain to pull it off. Just don't expect it to look impressive for a loooooooooonnnnnnnnnggggggg time

Just food for thought.