low tech tank problem

[juggler]

A week plus ago, my low-tech 1ft tank (no CO2/ no filter/ no dosing/ with 10W bulb) with the crypts suddenly got cloudy water. And fish started dying. The death toll: 3 x bumble bee goby, 10+ boraras maculatas. Not sure what had happened. Only the ottos, a coolie loach and a lone boraras lived. Many snails lived too. The plants look OK.

Any idea what could have happened? Tank water not changed since August. Only top-up.

A power shutdown in office lasting 3 days occured during Christmas. Not sure if this has any effect.

So far, the action I taken was to replace 3/4 of the water with used tank water from my main tank. Water still slightly cloudy but no more deaths.

Any ideas?

[SaceNexus]

you should change water.

Death of fishes i think should be due to ammonia.

[cherietung]

Assuming that yours is a conditioned tank with the livestocks exceeding 3 months and above, lighting on for 24 hrs.

Your 3 days of power shut down had resulted in mass accumulation of nitrate with no photosynthesis occuring for this period in time.

Having said about the nitrate, it is not the main cause of the deaths but the combination of the high ammonia and nitrate level.

Your fishes have been adapting to the high level toxic, but the sudden change for the 3 days was too much for the fishes.

Moreover, for a low tech 1' tank, it is way overstock.

In my view, not more than 4 1" fishes for such setup.

[juggler]

My lighting is about 10 hours.

Funny thing is that none of the other tanks in the same office suffer any setbacks. A Swordtail tank (similar size) with about 20+ size juveniles (> 1") in tank of Java Moss all survived the 3-day darkness. So did 4 other such tanks without filters or CO2.

Perhaps the only difference between the death tank and the others is that the death tank has a substrate whereas the rest don't. And the bacteria in the substrate died and caused some ammonia spike???

Anyway, I have done the water change, will see if it gets better. Will stock with lower number of fish too.

kf

[bclee]

I think it might be low oxygen level. The cloudy water may be an indication of bacteria dying off. In a low-tech tank, the substrate is alive with micro-organism. When there is no photosynthesis to supply oxygen, the bacteria have probably oxygen starved. Also be watchful to see if your substrate has gone anaerobic releasing toxic H2S and NO2.

BC

[juggler]

Interesting. So the substrate has more bacteria than a non-substrate tank?

So far I have changed water and tank still cloudy. Almost all the fish have gone now except for the two Oto.

Not sure how long will it take for tank to restart again? Will aeration of the water help?

Incidentally, my main 3ft hi-tech tank with base fert and CO2 injection/ filtration did not suffer any major setback. Only 3 casualty during the 3-day blackout.

Looking at the big picture: If our earth were to suffer complete darkness for a period of time, I am sure the impact will be devastating as well. Like what the asteroid did that wipe out the dinosaurs.

[d2hpeter]

i hv one in my office. Put floating riccia covering about 2/3 of surface, java fern, a very small pump for very slow water circulation, about 9hrs lighting, a zebra snail to clean wall and a yamato shrimp, fish load about 11 x 1 inch.
hv not changed water for 4mths plus, both riccia and java fern growing and fishes in perfect condition.
i reckon that the floating riccia is critical in the 'purifying' process.

18w lighting for 9.5"x9.5"x12"deep tank.

virtually maintenance free so far, except with a few dashes of flake food once every 2-3 days.

[vinz]

KF,

I suggest you try S. subulata temporarily. They seem to be able to handle bad substrates quite well. Their roots will re-oxygenate the substrate.

[juggler]

Thanks, Vinz.

S.subulata really has deep roots. You still have those I passed you? I have given up on those. Maybe will try E.latifolius.

BTW - I checked with Diana Walstad and she said that the fresh soil substrate especially have a lot of bacteria digesting the soil organic matter and therefore consumed a lot of oxygen. When that supply was cut off, they died off together with the fish.

I am now changing the tank water every few days as well as aerating the tank. See how it goes...

Thanks for all the inputs. It was a learning experience for me too.

[vinz]

I find Echinodorus don't do so well in bad soil conditions.

If you want SS, let me know. I given up on them as foreground, but I let them roam free in my 6ft tank... they add nice natural accents here and there and they are great at occupying unplanted ground in out of sight areas... keeps the soil in good condition.

[stocker]

[quote:e9b3b05c3e="vinz"]I given up on them as foreground, but I let them roam free in my 6ft tank... [/quote:e9b3b05c3e]

Vinz, pardon my ignorance, but why did you give up on them? Is it they grow too fast or too high or...?

BTW, any idea where I can get a some of these, what does Teo call them?

thanks!

[Simon]

[quote:bef849b233="stocker"][quote:bef849b233="vinz"]I given up on them as foreground, but I let them roam free in my 6ft tank... [/quote:bef849b233]

Vinz, pardon my ignorance, but why did you give up on them? Is it they grow too fast or too high or...?

BTW, any idea where I can get a some of these, what does Teo call them?

thanks! [/quote:bef849b233]

high maintenance? I think u can get some from KF or Vinz..

IMO, choice of foreground plants for larger tanks (6ft and above) is very important, not unless you have the time for maintenance. I try to select a simple and almost maintenance free plants (perhaps bi annually maintenance of foreground)

[stocker]

[quote:304f88="Simon"]
high maintenance? I think u can get some from KF or Vinz..

IMO, choice of foreground plants for larger tanks (6ft and above) is very important, not unless you have the time for maintenance. I try to select a simple and almost maintenance free plants (perhaps bi annually maintenance of foreground) [/quote:304f88]

erm, sorry, what do you mean by that huh? they grow too fast? What if I'm using them in a low-maint tank, slightly above 1wpg?

Also, what would you consider maint-free plants? like E.Tennelus or Marsilea crenata?

[joe]

[quote:2db8399d9a="Simon"]IMO, choice of foreground plants for larger tanks (6ft and above) is very important, not unless you have the time for maintenance. I try to select a simple and almost maintenance free plants (perhaps bi annually maintenance of foreground) [/quote:2db8399d9a]

Simon, wat are your recommendations? Hairgrass? Moss?? :P

[vinz]

With good light, CO2 and ferts, SS will grow short and fast. It covers ground very quickly. They require frequent pruning... about once every 2 weeks to prevent the filed from getting too dense.

If left alone, they will get too dense and start to shade each other. To compete, they grow longer leaves, resulting a too tall foreground.

They will also spread under other taller plants. Due to light limitation, they don't grow as dense, but will sprout long leaves to get light. They can get up to 2ft or taller. I allow them to do that in my 6 ft tank. This result in a few long strands of SS poking out here and there over my scape... giving it a more wild and natural feel. Every few weeks, I remove a few of them.

The other reason I let them wander in my tank is to keep the substrate oxygenated where there are no plants.

In low light, no/low CO2 environment, they will survive. The leaves grow to about 10cm long and they will spread out slowly, evenly, and sparsely. Hardly any maintenance is required if you don't care where they grow.

[stocker]

sounds good...

can spare me some anyone wanna "dispose" their excess?