How to make tank safe again after using wrong silicone?

I made a cave out of pvc elbows, lava rocks, and GE 100% silicone 2 kitchen and bath not knowing about the mold inhibitors. I put it in for a day and half I lost all my fish so I took out the cave did 100% water change and then filled it back up and then got 4 new fish added live bacteria in a bottle and lost 3 of the 4 fish and I’m about to loose the 4th. how do I make my aquarium safe again? when I decide to try again. Is my tank ruined or what can I do to clean it and make it safe

 

How long has your tank been set up? Did you cycle it? How? What are your water parameters?

 

It was set up for 8 months it was fully cycled water parameters where good fish where in there for 4 months then I added the cave and then everything when boom I emptied the tank and then filled it back up added live bacteria checked water added the fish checked water parameters where good and the next day 3 of the 4 fish where gone and I have 1 still holding on but is in rough shape and it’s gills are red

 

It was set up for 8 months it was fully cycled water parameters where good fish where in there for 4 months then I added the cave and then everything when boom I emptied the tank and then filled it back up added live bacteria checked water added the fish checked water parameters where good and the next day 3 of the 4 fish where gone and I have 1 still holding on but is in rough shape and it’s gills are red

Most fish have red gills, it's where they get and exchange oxygen in their bodies. Can you give us the exact parameters? pH, ammonia, nitrite, nitrate?

How often do you do water changes?

What fish do you have?

If you added the cave and everything collapsed, what can you tell us about the cave? What's it made of, where did you get it, how did you clean it, etc?

It's possible, if the cave is the problem, that it introduced something into your tank - excess bleach, dish soap, another detergent, etc.

Please let us know.

 

I wonder if some of the silicone mold inhibitors got into the filter and substrate?

 

Most fish have red gills, it's where they get and exchange oxygen in their bodies. Can you give us the exact parameters? pH, ammonia, nitrite, nitrate?

How often do you do water changes?

What fish do you have?

If you added the cave and everything collapsed, what can you tell us about the cave? What's it made of, where did you get it, how did you clean it, etc?

It's possible, if the cave is the problem, that it introduced something into your tank - excess bleach, dish soap, another detergent, etc.

Please let us know.

Parameters where always ph 7.6 ammonia 0 ppm nitrite 0 ppm nitrate 10 pmm I like to keep them at 5 or 10

I did 10 to 25% water change every week

They where 3 fantail goldfish 1 black moor goldfish same with the second set

The cave was made out of lava rock that was washed with just water, pvc 4 inch elbows, and GE 100% silicone 2 kitchen and bath I let it cure for 3 weeks before putting it in the tank got all the supplies from Home hardware built it myself

I never use soap or bleach on anything

I wonder if some of the silicone mold inhibitors got into the filter and substrate?

That was kinda what I was wondering how do I clean the sand and filter sponge ? Or should I buy new sand and filter sponge ?

 

Parameters where always ph 7.6 ammonia 0 ppm nitrite 0 ppm nitrate 10 pmm I like to keep them at 5 or 10

I did 10 to 25% water change every week

They where 3 fantail goldfish 1 black moor goldfish same with the second set

The cave was made out of lava rock that was washed with just water, pvc 4 inch elbows, and GE 100% silicone 2 kitchen and bath I let it cure for 3 weeks before putting it in the tank got all the supplies from Home hardware built it myself

I never use soap or bleach on anything


That was kinda what I was wondering how do I clean the sand and filter sponge ? Or should I buy new sand and filter sponge ?

Huh, great parameters for such messy fish - good on you! What's the water temp? Goldfish prefer colder water, which is also something I'm wondering about..

Oddly enough, colder water (under 71 F) tends to lock down/slow down the emission of chemicals from decorations, etc. added to the tank. It doesn't stop them, just slows them. So I'm wondering if DontheMon is right in a way. It's possible!

My guess would be either the GE silicone or the lava rock... lava rocks are great, don't get me wrong. My other hobby growing up besides fish was geology and I have a ton of lava rock samples. They can give off chemical gases and also particles in the water.

Can you take out the cave with the silicone and the lava rock? Leave them out of the tank for 2-4 weeks through water changes, etc. and see how your fish do. Do you still have the 1 fish left...?

Try this, and see how your last little guy does - if he hangs in there after a month, add the lava rock back in and watch closely. If he doesn't react/is okay, then I'd say the problem was the silicone.

There's industrial silicone, like you mentioned for kitchen and bath and then there's aquarium silicone which is MUCH different. If you want to build caves, etc. in the future use ONLY "aquarium grade" silicone.

Let us know how you get on, we're here to help!

EDIT: Cleaning sand - make sure it's not too deep, 1 - 2.5 inches is best. Deep sand can trap and grow/harbor really deadly gasses unless it's stirred/mixed up a lot so stick to shallow sand levels. To clean it, you can use your usual gravel vac during water changes but here's a tip: using the nose of the siphon, swirl it a bit in a clockwise or counter-clockwise motion. Think of it like making concentric circles as you move it around the sand bottom of the tank. If you suck up the debris into a bucket and you get some sand in there, don't worry too much. You can toss it all out. With sand substrate, do NOT go down the drain or the toilet. Toss it outside. You can always add more sand after properly rinsing it, over time.

Sponge filters, you want to tug them off and very gently clean them in the bucket with your syphoned water. Don't get aggressive with it - just lightly squeeze it a few times and gently try and brush/get away any bigger debris on the outside. Remember, good bacteria are also on/in that sponge so be gentle. Always do this in a bucket/container with the removed tank water - then after a minute or so, place it back in the tank.

 

Huh, great parameters for such messy fish - good on you! What's the water temp? Goldfish prefer colder water, which is also something I'm wondering about..

Oddly enough, colder water (under 71 F) tends to lock down/slow down the emission of chemicals from decorations, etc. added to the tank. It doesn't stop them, just slows them. So I'm wondering if DontheMon is right in a way. It's possible!

My guess would be either the GE silicone or the lava rock... lava rocks are great, don't get me wrong. My other hobby growing up besides fish was geology and I have a ton of lava rock samples. They can give off chemical gases and also particles in the water.

Can you take out the cave with the silicone and the lava rock? Leave them out of the tank for 2-4 weeks through water changes, etc. and see how your fish do. Do you still have the 1 fish left...?

Try this, and see how your last little guy does - if he hangs in there after a month, add the lava rock back in and watch closely. If he doesn't react/is okay, then I'd say the problem was the silicone.

There's industrial silicone, like you mentioned for kitchen and bath and then there's aquarium silicone which is MUCH different. If you want to build caves, etc. in the future use ONLY "aquarium grade" silicone.

Let us know how you get on, we're here to help!

Water temp was always around 72F to 74F I would put ice water bottles in the tank to cool it down as my house is quite warm

I have emptied the entire tank have the sand in a bin I am going to wash the sand with boiling water and my last fish just passed away in my snail tank so had to do a water change on that tank I have a total of 5 tanks in my house lol the goldfish tank is my biggest (65 gallons)

Should I soak the cave for a month and cycle my tank again and try again? Or should I rebuild my cave with aquarium silicone and new supplies?

 

Water temp was always around 72F to 74F I would put ice water bottles in the tank to cool it down as my house is quite warm

I have emptied the entire tank have the sand in a bin I am going to wash the sand with boiling water and my last fish just passed away in my snail tank so had to do a water change on that tank I have a total of 5 tanks in my house lol the goldfish tank is my biggest (65 gallons)

Should I soak the cave for a month and cycle my tank again and try again? Or should I rebuild my cave with aquarium silicone and new supplies?

Ooh no, I'm sorry to hear you lost your last little guy!

So long as your filter media is still intact (you didn't clean that yet did you?) you can probably go ahead and clean the sand. Boiling water is good for sand but I will caution you - STIR IT FREQUENTLY, otherwise whatever pot it's in might get ruined and don't boil for more than 10 minutes while stirring. Be sure to drain the sand fully and give it a final rinse in cold water, then try and leave it alone to dry out as much as possible if you can spread it out, The trouble with sand is it loves to store water despite being crushed up rock, LOL.

It might take 2-3 days of you stirring, spreading it out, etc. This just helps to ensure that there's no harmful bacteria hanging around in/on it. Putting it in sunlight is best but you don't have to be too crazy with it.

I'd also suggest cleaning the tank itself with a vinegar rinse - lots of water, splash or 2 of vinegar with the filter, etc. removed. Scrub it down real good, then rinse it really, really well and let air dry.

I'd say ditch the cave made with kitchen/bath silicone - make a new one, using ONLY "aquarium grade" silicone and leave out the lava rock for now. If you want, later, I can tell you some at home tests you can use on your rock to see if it's leaking anything.

Does your filter have the option for carbon? If you don't want to totally start over, carbon in your filter would be a great option to help remove any of the left over chemicals.

If you have carbon, start up your tank like you did before but let it run about a week before you add fish flakes, etc. to start a non-fish cycle. This will allow the carbon to, hopefully, pull out any remaining chemicals in the rest of your filter. Then remove the carbon, and cycle as normal using your filter media to start you off.

Let us know if you need anything, and I hate to ask this since you just lost your babies but... this time around. what are you going to get?

 

Hey so I also used wrong silicone but on the tank. I haven't put anything in it yet but I want to. I put a lot of work into it and I'm wonder if I can place aquarium safe silicone over the toxic one to help prevent any problems or should I just scrap my whole project?

 

Hey so I also used wrong silicone but on the tank. I haven't put anything in it yet but I want to. I put a lot of work into it and I'm wonder if I can place aquarium safe silicone over the toxic one to help prevent any problems or should I just scrap my whole project?

New silicone doesn't stick to cured silicone and you can't guarantee to perfectly seal all of it. You will have to re-do the whole thing. Sorry.

 

New silicone doesn't stick to cured silicone and you can't guarantee to perfectly seal all of it. You will have to re-do the whole thing. Sorry.

well that's saddening news. Thanks for the feedback.

 

Update: I managed to redo the silicone seal and it was fine for a while, even had my fish in there but then it started leaking and I don't even know where the leak is... does anyone know how to find a leak in a concrete aquarium or is there any products I can add to the water that'll at least help seal it??? It's a small leak and it took five days to reach the level it is now while I tried looking for someway to figure out what to do. I came across bentonite clay for ponds but I'm not sure if it'll work for a situation like this. Please send feedback, thanks in advance.

 

Update: found a solution and everything turned out fine