Dude. You dont need to seal concrete.okay so i found some 5:1 epoxy left over from a project a while back. even tho its not marine grade it should work right?... lol there will be a part where it sit in the water completly and a part where water is constantly running over it. its this stuff brushable? i looks pretty think so idk if it wil be possible but im gunna run some practice runs on a small trial piece just to make sure.
ps thanks for everyones information and help its greatly appreciated
I think you just interpreted my meaning of "leak" differently; I simply meant that any water running over the (uncured) concrete will have its pH changed by a reaction with the concrete (I was using the term "leak" here to mean the uncured freelime coming out of the concrete to interact with the water).You need to do a search on this. I had a similar thread at one point. The cememnt does not "leak" to change the ph. It only chanes the ph of the water if it is not fully cured. Its the freelime in the concrete that raises the ph of the water if not cured properly. Also, vinegar IS NOT the way to do this... trial and error i found this out myself. Vinegar eventually just errodes the cement, and the acidity of it doesnt do anything to help the curing of the concrete which is the root problem. Carbon dioxide is what cures free lime. The technique is to get some dry ice and seal it up in a container with your concrete and t will cure much faster than if left in open air. There is a previous thread with info from another member that seemed to be more of an expert at this than myself if you ue the search feature.
Many people in the aquaria hobby do use Drylok successfully. I personally have tried and will not use drylock (for THIS purpose, it has many other great uses!) because, in my opinion, it looks very fake when it dries whereas the cement mix (i use precision grout actually) dries to a much more "stone-like" finish.What about the Drylok idea? It is cheap, natural, and safe (unless more experienced people tell us otherwise).
"DRYLOK is a concrete and masonry waterproofing paint manufactured by United Gilsonite Laboratories (UGL). It is available in both latex and oil bases, and is tintable to a handful of different light and pastel colors to complement decor. DRYLOK forms a barrier against hydrostatic pressure---the force that water exerts against a surface due to gravity---to prevent water seepage through concrete. DRYLOK can be brushed or rolled on, and does require two thick coats to be effective. DRYLOK can only be used over Portland cement-based concrete, and is only effective as a waterproofer when used as the first coating over the bare surface."
More info: UGL - DRYLOK® Masonry - Masonry Waterproofer
One gallon of that stuff costs only about $9, and you won't need that much anyway since it is enough to cover 75 to 100 square feet of surface area.