Your tank is absolutely stunning. No wonder I could never find the plant gold. You should sell some of it on the S&S with a picture of your tank. It is very well scaped and such health plants!
By the way, the stress coat could have caused the crash. Have you seen the ingredients?
5%-30% aloe vera gel by volume,up to 7.5g/l carboxymethyl celluse,about 1.3 to 25g/l polyvinylprrolidone,about 12.5 to about 60g/l sodium thiosulfate.up to 2g/l elthylenediainetetraacetic acid,about 0.3 to about 1g/l tris(htdroxymethhyl)aminomethane,and about 1.3 to about 4g/l diazolidinyl urea.
In regular doses it is fine, it is when you overdose you can actually cause an ammonia spike. I killed off a whole tank this way last summer.
Without Algae, death of mankind would be inevitable.
Hmmm...I've dosed Stress Coat this way for years...but normally in much larger tanks so the ratio wouldn't be so drastic. Hmmm... I'll keep that in mind next time! Urea, eh? That's no good!
Geeze, makes me worry about the fact that at petsmart we used to put two pumps of the stuff into the little tiny plastic bag with the fish for their ride home! Here guys...have a massive dose of urea.
Urk! I just looked up diazolidinyl urea on wikipedia, here's what it had to say: " Diazolidinyl urea is an antimicrobial preservative used in cosmetics. It is chemically related to imidazolidinyl urea which is used in the same way. Diazolidinyl urea acts as a formaldehyde releaser."
Hmmmm...suddenly I'm seeing Stress Coat in a whole new light. I've been told for soooooo long that it is harmless in just about any dose. But now I think I'm going to have to use this stuff more carefully.
never used stresscoat, but good to know, phoenix... imo its best to stick with what works for each of us, i've done things that are not "conventional" for tanks and it works just fine for me, so there is no need to work on something that is not broken
ADA 120p - 65 gallon planted community
Eclipse system II tall - 30 gallon planted
6.6 gallon nano planted red cherry shrimp community
AGA standard 55 - 55 gallon mixed cichlid
So yesterday was my monthly 10% water change day. I syphoned up the sand and noticed a little more icky black stuff than normal, but nothing alarming. Everyone was happy and swiming around. After the water change (and yes, I remembered my Stress Coat, I put in about six times as much as I need) the fish looked more stressed than usual. I chalked it up to the fact that I had discovered another baby betta and I kinda spent a little too much time chasing him around the weeds.
So I turned off the lights for the day and let everyone rest.
This morning the tank is a murky white, it REEKS, half the shirmp are dead and everyone is skimming the surface.
The ammonia has spiked so high it is embarassing.
My prize betta Albi male is in this tank getting a rest from the female, he's white as a sheet. I pulled him out and dripped him to the grow out tank. Once in the grow out he darkened again, but his gills are cherry red and he's breathing hard.
I've just done another 10% in desperation and the fish are settling down.
The question is: what would cause this sudden break down in a very well established, full planted tank? I checked the DIY CO2 and there has been no back up, its running just fine.
I've known tanks to crash like this when the owner hasn't cleaned in ages and then suddenly does a 75% water change, but I only did 10% and I do it on a monthly baisis.
It sounds like your sand substrate which compacts very easily compared to other substrates became anaerobic (lacking oxygen). The anaerobic bacteria which grow under these conditions will release toxins into the water such as hydrogen sulfide, which is toxic to plants and fish.
Since your sand substrate is so light in color you would be able to tell when the sand was becoming anaerobic because it would start to turn black. When someone is using sand as a substrate, it MUST be stirred gently on a weekly basis to avoid toxic areas occurring.
If the sand becomes anaerobic, pockets of hydrogen sulfide gas will form and when those pockets of gas are disturbed it will be released into the water column, killing and/or greatly harming the inhabitants.