Sinking A Diy Insert, I Need Help

Discussion in 'Freshwater Beginners' started by Bobito, Mar 30, 2019.

  1. BobitoNew MemberMember

    Goal is to sink an aquarium insert. I made an aquarium insert that floats. I have enough room to put rocks or anything heavy in the bottom to make it sink but it needs to be a lot.

    I bought diver weights and covered them in free form habitat black putty and two coats of tar-bender to encapsulate the LEAD. I found this sinks the insert by putting 20 pounds of the covered diver weights. I’m worried the LEAD will leach through and kill my crayfish/fish. What is the safest and most dense rock to use that will fit in a hole about 3 inches by 3 inches? Is it safe to encapsulate LEAD. What is my best angle?

    Attached Files:

  2. BobitoNew MemberMember

    I can’t drill to let the air out because my ex girlfriend painted sponges to harden them. The free form habitat black has that encapsulated but I don’t trust the lead so I need something heavy that won’t kill crayfish and fish.

    Would cement brick work to weigh it down? if I break it up? I learned certain bricks have lime and chemicals so I am unsure what to do
  3. mattgirlFishlore VIPMember

    Is this piece totally sealed? You say you can't drill holes in it but I wouldn't think it wouldn't be a problem to drill holes in the bottom of it unless it is a solid piece of material. If it is hollow just turn it upside down to allow it to fill with water and then turn it right side up while still holding it under the water. I wouldn't think it would take much weight to hold it down once filled with water. I know plant weights are made of lead and are used in aquariums without causing problems. I am not sure about the weights you are using though.

    It is possible I am missing something here though.

    I just re-read the OP. I just thought of something. Maybe you could fill the holes with something like Matrix held in there with hot melt glue. I wouldn't use brick.
    Last edited: Mar 30, 2019
  4. BobitoNew MemberMember

    I posted pictures. The bottom I already cut open to put rocks or weights in. The air is in the sponges (I won’t use a sponge again) which are in the middle. I can’t cut the sponges because of the paint she used on them.

    Plant weights are LEAD? That is helpful. I didn’t realize that. Thank you, maybe it won’t leach. I can test it in a ten gallon aquarium if I can’t find a better option. It’s hard to test in the 300 gallon because it’s so high and the insert is 50 pounds already. The sponges work like a dock on a lake haha. I didn’t think they would hold this 50 pound insert. When I add 20 pounds it’s perfect. The plant weight thing may help. Thank you

    I released all air I can safely release.
  5. mattgirlFishlore VIPMember

    When I re read what you said and got a bit closer look at the photos I can see better what you are seeing. It is hard to tell from the photos how much hollow space there is to work with though. I know you said the holes are about 3 by 3 but I didn't know how much hollow space there is.

    My only suggestion is filling the void with something like matrix glued together/filled with either aquarium safe silicone or hot melt glue. the matrix would serve double duty. Hopefully hold the piece down and a place for bacteria to live.

    I can see your quandary when trying to sink something that is actually designed to float :D

    Hopefully someone here has been in your shoes at some point and will share what they did to make it work. That is a beautiful piece so well worth the aggravation of getting it to stay where it needs to be.
  6. MrBryan723Well Known MemberMember

    Lead is mostly inert(doesn't really leech unless under special circumstances) and crustaceans don't have a hippocampus(which is what lead molecules disrupt) so it's basically harmless to them. Also it has very little impact of fish and reptile species but don't eat them of course because it is still present in their systems.(though usually small enough traces it is still mostly harmless)
  7. BobitoNew MemberMember

    I have spoken to several engineers. All three said it's a risk but it shouldn’t be a problem if I encapsulated the lead in tar-bender. I am putting four coats to be safe because it’s easy to apply. I will let y’all know how it goes if you ask on here. It would take about a year or so to have an issue because the process of leaching takes a while and my tank is 300 gallons. With water changes it should be ok even if a small amount gets in. My crayfish would go first so we will know soon. I have done a lot of research and I think It will be ok.

    I went extra safe and covered them with two layers of habitat black epoxy putty and now four layers of tarbender resin encapsulated. Thank you for your help