scrubbing algae killing fish

[reefscapes]

I do maintenance on a number of tanks and i have had this happen to me a couple of times now. it seems that when i scrub some algae that has been growing for awhile like on the back of a tank fish seem to be lacking oxogen. they start breathing rappidly then start swimming funny and end up on the tank bottom dying within minutes. i have lost firefish, tangs, gobies, chromis, is this possible nothing else was added or changed can scrubbing certain algaes deplete o2 levels that quickly

[Reefscape]

what exactly are you scrubbing the tanks with mate? algae mag, green scrubber, razor blade??? or something else?

Scrubbing algae of the glass should not be killing the fish...I scrub mine every other day...always have done...


Niko

[YoFishboy]

yea...that sounds like you are introducing something toxic into the tank when you clean...is someone using you scrubber for something else?

[reefscapes]

i use the same pads in all my tanks nothing special just a white algae pad again its old algae mabey a little slime here and there i always make sure they are clean nobody touches this stuff but me

[Reefscape]

all i can think of is something is leaching from the pad into the water column...if your doing nothing else or changing anything, it does kinda point towards your pad....

Niko

[joander123]

welcome to AC btw 8)

[Germanman]

yea welcome! what kind of filtration is on the tank and how else do u service it...like whats ur regular service

[reefscapes]

this is a 90 gal flatback hex with built in filter and skimmer in the back never had much problem with it coral all do well had a red slime problem dosed with a new product from blue coral for slime ran carbon and changed 20% slime is gone. last week i cleaned gravel line and kicked up sediment from gravel it killed a firefish and a yellow tang within minutes clown and scooter blenny survived as did all the coral. today i added a bar goby and a kole tang both looked fine then scrubed the back of the tank to remove excess algae and then both fish went into serious shock breathing hard and could not keep equilibrium dead in less than half hour. i know its not my pads as i use them all my tanks that i maintain and dont see these problems. tested calcium at 350 alk at 9.6 dkh im wondering if their might be some toxic state caused by dosing this red slime remover that lays dormant in the sand and or on the back of the tank until it gets stirred up. i had a similer problem in a 400 gal some time ago again it was after i scrubed of the back wall of some thick green algae with a little hair algae mixed in killed numerous fish same way looks like o2 deprevation all fish die with gills wide open seem to be gasping for air. again all coral seem fine i ordered a o2 test but thought coral would suffer as well with low o2 levels i am at a loss not to mention this tank is in a doctors office so everybody gets to watch this fish die :huh:

[Germanman]

i doubt its just th o2 what are the ammonia nitrate and nitrite levels and do u clean the gravel often? how often do u change out media?

[reefscapes]

tank has been running for about 5 years it was moved about 3 months ago i use seachem's reef builder and calcium supplements water change every other week carbon is changed out every month use reef crystals salt seachem's phosguard when needed havent checked ammonia or nitrite but pretty sure its nonexistant. nitrate around 50ppm most my tanks run this high without a problem whatever is doing this seems to happen when either i scrub algae or turn over the sand it seems. i dont vacuum the sand but am considering doing so tank runs 80 salt at 1.020 have you heard of TOXIC algae???

[WeeNe858]

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

[5xevy]

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.

Welcome to AC!

[WeeNe858]

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

[Germanman]

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.

[Fishieness]

if they gasp for breth and die its cuz theres to much of somthing in the tank..

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?

[m007]

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......