Overflow Teeth Cutting

[uncleof6]

Must be working ok, undetectable levels, great SPS color, excellent growth, excellent polyp extension. As far as fish jumping, your post is QUITE a stretch, but my best guess would be flow related. I generally run over 100x turnover in my sps tanks. Some fish like it, some don't. Who knows, I don't have 35 years in the hobby, but I did stay at a holiday inn last night.

Edit: Any photos of your system utilizing a non-toothed, 100% fish/snail safe overflow? I didn't see any in a quick search.

I am not here to post show and tell hour; very few of the books I read have pictures in them either...I have never spent a night in a holiday inn, and everything that approaches a science is considered to be a stretch, in this hobby it seems, but is only countered with anecdote...

Flow could be involved in some way, but if you consider we are not getting even remotely close to 'flow rates' on the natural reef, and ocean currents in general, it is not likely in terms of volume, quality of flow certainly. In the case of very delicate organisms such as seahorses with which high flow rates seem to cause their demise, it could easily be a factor.

I never said that any of my overflows are/were 100% fish/snail safe, It is more a case of I do not obsess over it, water quality is more important—it is all about water quality; it is not the huge problem it is made out to be. As was pointed out, there are more intuitive ways to deal with the 'risk,' if the concern is that great. Are we truly to accept 'ok' rather than the very best that can be given to the critters which we remove from their natural environment?

35 years just means more time in which to do less than brilliant things, make more less than brilliant mistakes, and buy into more marketing hype, than most others...

 

[uncleof6]

I am happy I found this thread as I am in the beginning of a new 120 build. I started building the stand today and started practicing glueing the acrylic for the overflow as I will be building that also. I understand the argument on the toothless weir and makes sense to me. If I do go that way do I need to lower the top of the weir in relation to the trim on the top of the tank. My last tank I installed a weir with teeth right at the bottom of the trim. If I do this with a plain weir will that be too high? The overflow will be 24"Lx6"Dx4"W. I plan on gutter guard or a solid lid with either slots or holes.

The flat weirs (plain weirs) are usually set right at the bottom of the trim on the outside of the tank. As was pointed out, the water level will be 1/8" or less, to around 1/2" or higher. It is a function of flow rate, and length of the weir. With a flat weir, at a given flow rate, this height will be less than an equal physical length of toothed overflow. There are mathematical calculations (called weir calculations) that can be used to determine how deep the water will be going over the weir (head height,) and the thinner this layer of water the better. e.g. at any given flow rate, the longer the weir, (effective length) the less the head height behind the weir, and thus the more efficient the surface skimming/surface renewal. Flow further from the weir moves slower than water closer to the weir...hence the higher the head height, the less surface water, and more subsurface water goes over the weir. Direct measurement (using a flat weir) can be used with the calcs to determine the exact flow rate of the system. (Well more accurate than guessing using flow curves.) This is what a weir is actually used for.

The water line will always be hidden when set in this manner.

 

[Gorgok]

I want to house separate pairs of clownfish, share the same water, and not need multiple drains and returns. The teeth are simply to let water flow through each chamber.

Are you concerned with them seeing each other? Eggcrate would be capable of separating the tank into smaller tanks for decent sized clowns... not so much for tiny ones. It would also let you give them some flow throughout the tank without having individual powerheads in each section.