I have a small problem....

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Aquarium Advice Regular
Feb 19, 2009
Hamden, CT
In the process of cleaning my new tank, which was given to me by a coworker. I found something pretty unfortunate. My tank has an integrated wet/dry filter. The rear of the filter is sectioned off by acrylic inserts and some grating. I noticed that at some point, a fish or invertebrate of some sort managed to get itself underneath the grating in the rear of the filter system and died. There is what appears to be some sort of skull bone? floating around in a trapped section, and in a second trapped session there is a brown slime that is pasted to the bottom of the tank. I attempted to clean this yesterday when I realized in my frustration that it seems to be completely unreachable. The acrylic inserts which separate the filter section are permanently joined to the tank, with the rear grating permanently joined to the inserts. There seems to be no feasible way I could access either of these issues to clean them. The tank is currently filled with a bleach solution with the filter running, hoping to clean out any bacteria / disease that was present before I recieved the tank.

I don't know what to do about what appears to be remains, I can't access them to clean it out, will the bleach cleaning suffice to kill whatever bacteria / disease could be present from the remains?

I really was hoping to get this tank running and I'm afraid if I don't clean up this issue it will cause a lot of problems.
I would say it depends how big a pile of remains we're talking about. I wouldn't worry about the skull, but if the brown spot is the rest of the fish you might have a problem. I'm pretty sure bleach will kill anything, but any bacteria that eat a dead fish are likely equipped to eat a live one too, so I would be careful.

What I would suggest is that you pretty much ignore it, and just make sure you do a fishless cycle. By the time that's done, the thing should be done decaying, and leaving the tank without fish in it for that period should prevent any fish diseases from surviving.
Use white vinegar and let it soak.

Thanks for the tips. Since I posted this thread, i filled the tank with a bleach / water solution. And ran the powerhead for about 24 hours. When I did a full water change I noticed that some of the "brown stuff" had been washed away and what remained was now more black in color. I did a complete water change and refilled the tank, I de-chlorinated and added substrate in, I'm going to check the levels today and determine if I need to do another water change or not. Im hoping to move forward with the cycle. That and I'm about to get my hands on some legos for some aquarium decoration building.
legos, eh? You'll have to post pictures of those ;)

I plan on it, I've been taking pics at all stages of my entrance to the aquarium hobby. From the dirty empty tank and ugly base, to the cleaned tank and refinished base, I'll be taking more pictures soon now that I have it setup and filled (just gravel and water right now) and I will definitely takes some pics of the legos. What else am I going to do while it's cycling??? :clown:
Can't wait to see the legos!

Maybe you can fill each one with silicon to hold em together!
And that should make it easier to keep them on the bottom... or where ever you put them.

Don't just think about the bottom though!
They could start on the sides of the tank with a bit of silicon to hold them in place!
So I started building and placing legos in the tank last night. Just a few things, I'm heading over to Toys r us today and I may actually buy some lego sets if anything catches my eye that would be good for the tank. Spongebob Square Pants anyone??? So far so good, pics will come once I'm confident in the setup but I created a "system" for keeping them in the tank and its working pretty well. Basically, everytime I build something, I create a "pillar" at the bottom of it, it only needs to extend an inch or two. Then I stick a good ole' flat peice on the bottom of the pillar and bury it in the gravel. The weight of the gravel holds the flat peice under, in turn holding the entire structure at the bottom. The bouyancy of legos isn't all that much so the actual force pulling up isn't too hard to overcome. The bigger the structure, the bigger the pillar / flat peice. It's working really well. I have blue and green gravel in the tank and I've found that if you use blue peices to create the pillar you can almost completely hide them, I have a lego shark that actually looks like hes sitting just above the gravel! My roommate and I were like little kids playing with legos last night, I can't wait to do more!
You should assemble them under water so that there won't be air trapped inside them.
That seemed to be more trouble than it's worth. Even if they were filled with water and no air in the gaps, the legos themselves are less dense than water. The most effective solution seemed to be burying them, not to mention putting together legos underwater is really annoying :silly: I'm really happy how they are coming out, I also got in the habit of using gravel in some parts to make it easier.
Well yes, but I don't image that it would take much force with some larger fish swimming around them to dislodge them from the base, and plastic filled with water is denser than plastic filled with air. Just a thought.
Well yes, but I don't image that it would take much force with some larger fish swimming around them to dislodge them from the base, and plastic filled with water is denser than plastic filled with air. Just a thought.

Yeah I know, I just meant to point out that even with filling them with water, you still need a way to hold them down. Water alone doesn't do the job, so rather than fill them with water AND secure them another way, it's a bit easier to just secure them the other way. I can definitely see your point about the fish dislodging them, that may require me to get a bit more creative with my engineering of the lego setup. I don't have any fish yet so only time will tell if that's a problem. I'm going to avoid any silicone or permanent fixation because 90% of the fun of legos is rebuilding and changing things around. If the pillar system doesn't suffice, I think the next logical step is to try a fishing line / heavy rock technique. As for now though, the pillars are working.
You could drill a hole down the center of the support pillars and just use a wire to hold them together.
As far as the 'sludge' goes-- I second vinegar or, if you can get hydrogen peroxide on to it, chances are it will fizz it loose from what it's stuck to and let it be rinsed away.

H2O2 would probably work best if used by itself though (so drain the tank below the level of wherever the 'sludge' is and let the H2O2 go to work... it eventually will become inert so it's safe to use in the tank).
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