Thanks for the responses, and, yes, several guessed correctly that the welfare of the fish is not paramount. The aquarium is setup to respond to customers that ask, "What have you got in this lake?" Simply point them to the aquarium, which has fish and other items that make it into the lake. While some folks commented that this may seem unsightly, the customers actually get a kick out of it - it's a hoot to see a key ring with Obama's name on it floating in the aquarium. It becomes like an I Spy game - they try to locate all the paraphernalia that is in the tank, including the fish.
Kelly: I appreciate your comments, thank you for your insights. The tank is 1/2 full because the store is actually floating in the lake and we get waves that make the water slosh from side to side. If the tank were full, the water would slosh over the sides/ends. While a first impression may be that the tank has "trash" from the lake, we try to spiffy the items up - fancy wine bottle, conch shells, fake skull of some creature, Obama's key chain, etc. The world is full of "cool" fish tanks, this one meets someone else's definition of "cool" that may not be mainstream and it does draw people in simply to look at the aquarium.
krichardson: That's our July 4th garb. The employees all get festive head gear and I get to paint my bald head red-white-blue.
While I make it sound as though I don't give a rip about the fish, the reality is that they are very hardy. The only fatalities we've had are Crappie that were bullied by the other fish, and catfish that slept all day under the rocks then bounce off the ends of the tank all night until they killed themselves. We've learned to not include those fish in the tank - so, we're not heartless.
A prime motivation for the consideration of marbles is that the coral substrate has nooks and crannies that harbor bacteria very effectively - which may be a good thing, but, tends to lead to excessive cleaning, especially at the end of the season when we clean out the aquarium. A possible side benefit would be that we could install lights under the tank - it has a clear bottom - that might make a nice effect as the light shines through the glass marbles. This is a minor consideration, the larger issue is reducing cleaning maintenance during and at the end of the season. While the use of marbles may reduce cleaning requirements, I'm not that much of a tank expert to discount that our filtration system simply may be inadequate. It may be that we don't have to consider substrate, but, should focus on better filtration options.
Bluegill, which we mainly have in the tank, pick up rocks and make their beds. Since they are prolific rock movers, I'd tend to doubt they'd have an issue ingesting marbles. I don't know any other fish we put in the tank that has shown any interest in the substrate - the ingestion issue may be less of a concern, but, something we appreciate being raised for consideration.
I dont think your going to be breeding them. why not stick to the stuff you already have. why not keep the tank running and set it up naturally and use it to teach the customers about the fish and lake? instead of keeping it half full and filling it full of trash from the lake. I think the customers would enjoy that and it might even boost business a little. I know I would go to a local marina if they had a cool fish tank. Im not telling you how to run your store those are just suggestions
