DONT kick up the sediment.. that might be giving your tank the spikes that kill your fish.. if you wann know for sure you can take the fishes you and test the water after you kick up the sand.. i can garenteee you that your lvls do a bit of a spike.... try to get a cleaner pack (snails,hermits) to do your sand cleaning all you really need to doo is scrub the tank walls and do your water changes
Hmmmm. Do you clean your scrubbing pad in between uses? If so, what do you clean/rinse it with? How long do you keep the filters off while doing maintenance on the tank (if you turn it off at all)? How much of the substrate do you stir up when you clean it? So you're saying this happens with brown algae, blue-green algae, and the red slime algae?
I'm just trying to figure out what it could be that's stressing your fish out to the point of death. I don't blame you for wanting to figure it out as well.
if they gasp for breth and die its cuz theres to much of somthing in the tank.. kicking up sand causes high nitrates.. or the sponge is secretly being used for toilet scrubbing
that specific gravity is a bit low i would never go below 1.023 in an aquarium. also try the test right after like the others recommended and i dont recommend phosguard because it leaches out aluminum.
this would be my guess. not only does it release sediment, but in an old sandbed, especialy one without a lot of hermits or anything or macro fauna walking over it (IE, a 5 year old sand bed without a clean up crew) you can have some serious stuff built up in there. not just nitrates, a lot of sulphates, even a lot of toxic gases that build up. that is my guess...
but also, how are you aclcimating these fish that seem to die right after?
I wouldn't be so quick to blame the scrubbing pad. I have personally experienced the same problem years ago with a 125G. Established algae, like the kind found on the back of tanks, feed on a number of waste nutrients generated by tank inhabitants. Scrubbing releases those wastes back into the water. Depending on how much algae you scrub and what said algae has absorbed various chemical reactions will begin. Since the fish breath the water what ever has been released will automatically end up in their gills. You get the picture. As far as substrate goes, I went down that road as well. At the time I was using a 4 inch bed of crushed coral and was not providing enough circulation in the tank. The substrate began leaching hydrogen sulphide killing just about every fish I put in the tank. The hydrogen sulphide molecules eventually embeded itself into the algae growing on the back of the tank with very fatal results. I finally removed all of the substrate and algae in one shot. (There were no fish left to kill). Performed a 50% water change and let the tank run. 3 weeks later another 50%. I never replaced the substrate. Years went by with no algae problems and many healthy happy fish and coral. Sorry for running off at the keyboard......
