Glass vs Polycarbonate for a lid

[BryanM]

I would think a glass lid would be very heavy as well.

 

[Euphylliaphyle]

I have one I fabricated from a 1/4"t piece of repurposed plastic (see build thread) that I thought was polycarbonate but is probably acrylic. It does warp over a week or two, but for me this is not a problem. It doesn't sag, though. The ends actually curl upward. I'm guessing this is because it is a hygroscopic material and may be lengthening on the water side the way a bimetal strip would do in response to temperature. I don’t care enough to research the actual "why." Since my lid is made symmetrically, I simply flip it the other way when I do weekly maintenance stuff. The cover is off anyway, so I rinse off any salt deposits, etc, wipe it dry, flip it over and it's ready for another week or two. No regrets. I probably wouldn't do it with a larger tank, though, where the curl would be more pronounced and flipping it may be unwieldy. For my 30"w tank though, it looks good and is fit for use.

 

[nycsteve]

What is the purpose of the top? If it's just to prevent fish from jumping or keep cats out, then a mesh top would be better. If it's for humidity reasons, then polycarbonate is a good choice. Greenhouse PC is nice because it's cheap and very light, but it uses two walls separated by ribs, rather than a solid sheet. The ribs and spaces tend to look less "finished," or more DIY than solid PC if it's visible. I don't think UV is an issue since most aquarium lights don't put out any significant actual UV (<400nm) even if the diodes are labelled as such. The thickness is a concern with solid PC in order to prevent sagging, but that depends on the size of your covers.

 

[nycsteve]

thanks for quick response. not sure what mesh is, you mean screen? wife would insist on a tight cover, splashing, cats , salt creep on walls and floor and house is very dry so evap would be a big issue

 

[Gumbies R Us]

thanks for quick response. not sure what mesh is, you mean screen? wife would insist on a tight cover, splashing, cats , salt creep on walls and floor and house is very dry so evap would be a big issue

When I say mesh i usually refer to the mesh screen door kits that you can pick up at a hardware store

 

[Fish Fan]

thanks for quick response. not sure what mesh is, you mean screen? wife would insist on a tight cover, splashing, cats , salt creep on walls and floor and house is very dry so evap would be a big issue

That's quite extreme

Salt creep isn't that bad at all. Many of us have cats with no issues. Splashing doesn't happen much, except with some fish like Puffers and when doing maintenance, and for that you can put some towels down.

You can't really have a tight cover, it's really important to have good gas exchange and tight fitting lids can limit that, especially if you don't have either a sump or protein skimmer which can both aid in gas exchange.

 

[penfold2]

thanks for quick response. not sure what mesh is, you mean screen? wife would insist on a tight cover, splashing, cats , salt creep on walls and floor and house is very dry so evap would be a big issue

I mean flexible netting like this. The vast majority, if not all splashing and salt creep occur when you're working in the tank and the cover would be removed anyway. You could put a small piece of polycarbonate or acrylic over the overflow if that is a source of salt creep. Evaporation is the main reason to use a solid cover. Homes in very cold climates can potentially have condensation and mold issues if humidity is too high. I would first try going without a solid cover to see if you even need it.

 

[Euphylliaphyle]

When I say mesh i usually refer to the mesh screen door kits that you can pick up at a hardware store

Have you ever measured PAR drop-off using such mesh? It seems as if a mesh that tight would act like a 50% shade fabric. Just asking, as I have no experience with it.

 

[Fish Fan]

Have you ever measured PAR drop-off using such mesh? It seems as if a mesh that tight would act like a 50% shade fabric. Just asking, as I have no experience with it.

You don't use typical window screen, many use the 1/4" mesh that @penfold2 linked above, with the frame kit @Gumbies R Us suggested. The 1/4" mesh blocks almost no light

 

[BZOFIQ]

Home depot sells parts to make your own mosquito nets for your windows/doors. Get a frame kit and then buy the mesh, back in the days BRS used to sell the clear or black 1/4" mesh.

Cheap and effective.

Get the hardware from Home Depot because its cheaper and pick your mesh here.

https://www.bulkreefsupply.com/1-4-...D=9584&indexName=brs_prod_m2_default_products
https://www.bulkreefsupply.com/clea...D=1768&indexName=brs_prod_m2_default_products
https://www.bulkreefsupply.com/1-8-...D=5579&indexName=brs_prod_m2_default_products

 

[BZOFIQ]

Found some old pictures of a DIY I did ages ago...

Step-By-Step...because I CAN be a nice guy.

Cut the frame pieces with a hand saw or better yet a miter saw if you have one.

On My old 180, possibilities are endless.