I have found that groves or gaps over 1/4" wide rarely get eggs when smaller or narrower gaps are present. Shape of the spawning device might play a role but I doubt it. IMO instinct tells the male SFS to not establish nor defend territory and for females to not lay eggs in wide spaces because way too many predators including many species of invertebrates have access to eat the eggs. The best gap spacing in my experience has consistently been 2 to 5 mm wide. Optimum gap width is easy to test. Build a spawning device with plates or disks that have different widths between the disks. During spawning season lift and check it where the eggs are being deposited. Been there done that using disk spacing from 2mm to 1/2" and IMO the research studies and literature are mostly correct the spacing of 2 to 5mm spaces will collect the most eggs.

In Snipe's case that he did not see very much recruitment in the pond from his spotfins breeders is probably because the newly hatched SFS fry were being eaten by adult minnows or shiners or the eggs for some reason were not hatching. SFS will eat their own eggs if the eggs are exposed and not well back into the crevice. SFS are prolific. The neat thing about SFS is when the spawning devices have lots of eggs, the device can be moved to a clean fish free pond for the eggs to hatch and fry are able to grow. I have grown lots of SFS in ponds with FHM and BNM present and no other fish. I think most all other shiners who eat zooplankton and small invertebrates will eat lots of newly hatched SFS. The SFS grower in my area had very good success growing SFS in his production pond until GFS invaded and production went down to almost zero. A pond draw down, renovation and a restart occurred this fall.

If you have adult SFS and with the correct spawning structure in a pond and you are not seeing abundant small SFS in mid to late summer, something somewhere is remiss. Remiss: careless in, or negligent about, attending to a task or effort.

Earlier questions from Stressless see below for answers
1. ? is there a 'sweet spot' on the number of crevices, ie., platters that should be in the stack
- Soak the platters in a watershed that has spotfins or any known shiner that is a crevice spawner. Bacially these are shiners in the scientific genus Cypinella.
2? How often should they be checked, moved to the pond
- remove the Platter Stack and bring back via a aerated conveyance if traveling a far distance such as more than 50 miles. Just eggs on a spawn device do not consume a lot of dissolved oxygen.
3? do the Platter Stacks need to remain vertical or can they be laid horizontal for transportation
- submerge platter stack in pond. Try to keep the spawn device off of the sediment on the pond bottom.
4? How long should they be soaked in the pond?
5? Any guidance on where in pond the platters should soaked for the eggs to hatch, deep/shallow water, shade/sun?
?6. how long from Fry to Breeding for SFS - in other words should I leave platters in the pond with no adults over summer or keep trying for eggs?

Thanks much Stressless/

Acrylic platters I’m not sure what these look like except those on eBay.
Aren’t they expensive? Plus the ones I found on eBay are shaped like paper plates that have the wide perimeter flair; bad idea IMO. As some have mentioned IMO easiest, most convenient plates or disks for me are cheap CDs. No preparation, cutting, or drilling is involved. You can also cut plastic sheeting into rectangles or squares.
1?. Number of crevices is directly related to the number of spawning adults and number of eggs desired. Any number of disks more than 2 individual disks to create a narrow crevice will collect eggs. Obviously the more disks in the stack the more egg laying surface that is present. One stack of 10-12 CDs can collect a few thousand eggs.

2?Frequency of checking devices?. During SFS spawning season, devices in the wild habitat for collecting eggs,, I think devices should be checked every two to four days.

3.? Do stacks need to remain vertical or can they be laid horizontal for transportation?
- submerge platter stack in pond? Just keep eggs submerged so they do not dry out.

4.? How long should they be soaked in the pond? This depends on water temperature and age of the eggs when collected; hatching usually requires 5-8 days.

5.? Any guidance on where in pond the platters should soaked for the eggs to hatch, deep/shallow water, shade/sun? If the pond has no predators eating plankton or fish fry, then soaking for hatching anywhere in the pond will be okay. I have hatched SFS eggs in a bucket of aerated pond water. Eyed eggs are best to use for bucket hatching and water exchanges are helpful prior to hatching. Shallow water has the warmest water for egg development. If the pond has turbid silty water, where silt can collect on and inside the plates then the stack is best placed so it receives some current and well oxygenated water from an aerator. In ponds containing fry predators, IMO the more dense habitat in shallow water the better. Newly hatched poorly swimming fry are very easy food items.

6.? How long from Fry to Breeding for SFS - in other words should I leave platters in the pond with no adults over summer or keep trying for eggs? IMO fry should be at least a full 1 year old to spawn, although those grown indoors could spawn less than 12 months old. Some websites say SFS do not spawn until 2 yr old.

Research and my experience shows the preferred gap spacing between plates is 1.5 to 3mm, however the narrowest spacing more quickly gets packed with sediment from turbid water and/or growths of filamentous algae. Depending on water quality the devices after a month or two can become very dirty or covered with FA. I have put dense FA infested spawning devices in a tilapia cage and the device was quickly cleaned. I prefer 2mm to 4mm. Spaces or gaps more that ¼ inch are too wide and uncommonly used for egg deposits. My SFS readily spawn in between clear CDs and white plastic sheeting. Other colors will also receive eggs. I hang my devices from the dock with 6” to 18” of water over the devices. Most eggs seem to be collected on devices hung with water 6”-12” on top of the stack. Those in 3ft of water receive only a few eggs.
I collect and clean the spawning devices each fall or spring prespawn. IMO clean surfaces for egg deposition result in best egg hatching. I hand clean my all my devices and a pressure washer works well.