Bizarre Bar Goby behavior; HELP!!!

[Lemonhead]

Has anyone noticed their bar gobies/ zebra dartfish crashing headfirst into the open sandbed and them returning in the water column to swim? All 3 of mine have been displaying this behavior on and off since I purchased them several weeks ago.
My tank is 5 weeks old and running well. All my levels are within normal range. None of my other fish are behaving abnormally. They are not darting out of fear from predator fish as all my fish as peaceful. I just wondered if this is a normal action or maybe a mating dance.

[ToddTT]

I purchased them several weeks ago.
My tank is 5 weeks old

They are probably severely stressed.

Have you read this yet?

Setting Up a FOWLR Aquarium

What steps did you follow, and what fish/inverts/rock are in your tank right now?

[ToddTT]

Also, are you familiar with flashing in fish? This is when they rub or strike against rock or substrate, often a symptom of parasites.

[ToddTT]

You should read ***all*** of the stickies on this site, including:

Setting Up a FOWLR Aquarium

A Fish Quarantine Process

Stocking the Marine Fish Medicine Cabinet

Not that your fish have ich (not enough info yet), but you should read this to prepare for the possibility:

Marine Ich - Myths and Facts

Do not administer any treatments until there is positive identification of an ailment or parasite.

And listen to the advice that is sure to follow.

[Lemonhead]

Thanks for the quick response.
I have read info on systems for months prior to taking on this hobby. The tank is a 72 gallon bowfront I was given free from a patient who couldn't enjoy the hobby any longer.
I used premium live rock and sand in the tank. They "seasoned" for 2 weeks prior to introduction of inverts as instructed by the Aquatic store I freq near my home.
I have 6 Nassarius & 6 Margarita snails; 4 Blue eyed and 6 blue legged crabs; 3 Peppermint shrimp who ate my nasty Aiptasia. (Thank GOD!!)
There is also 2 cleaner shrimp as well. Other fish were introduced several at a time once weekly.
I have a Tailspot, Lawnmower blenny, Yellow watchman (Lemonhead), 2 clowns, Coral Beauty, Flame Angel, McCosker's Flasher Wrasse, Hippo, and a Chalk Bass. All specimens are small so I can enjoy them longer. They have lots of swimming room.
I have a refugium with a skimmer on line. I use Charcoal and Phosguard in the sump compartments.
Heater is up and running with alarm settings as a precaution.
Partial Water changes have been happening weekly due to fish acclimation. All readings for Salinity, Alk, ph, Ammonia, Nitrite, and Nitrate are withing normal ranges.
The 3 Bars swim in the tank during the day acting as though they haven't a care. At night when I go to bed, they all 3 retreat into a burrow under the rock. The Watchman has now joined as their guard.
I have no clue!!! I'll keep you posted if I figure it out.

[Lemonhead]

More thanks!!
My fish were in a Copper, low salinity tank at the Aquatic store for at least 5 days prior to purchase to help kill off any parasites. I have not noticed any ich on them at this point.
I do know what ich is as I also have a Freshwater tank (10 years now) and have had a problem several times.
There could be a problem that has not rared it's ugly head yet. I will not medicate until I know that a parasite is indeed the problem.

[ToddTT]

More thanks!!
My fish were in a Copper, low salinity tank at the Aquatic store for at least 5 days prior to purchase to help kill off any parasites. I have not noticed any ich on them at this point.
I do know what ich is as I also have a Freshwater tank (10 years now) and have had a problem several times.
There could be a problem that has not rared it's ugly head yet. I will not medicate until I know that a parasite is indeed the problem.

Typical ich treatment with copper requires more than 5 days, so it cannot be ruled out.

I hope you avoided dumping the LFS's water into your tank. This is a good practice in general, and especially if you know the water is contaminated (copper).

Unless I am misunderstanding your tank's history, it sounds like you have introduced too much livestock too quickly.

At a minimum, you may also have compatibility issues with your two angelfish. Keep an eye on these two, to make sure they are not fighting or stressing each other out.

Others will ask for your exact levels, so I guess I will beat them to it. What are your exact readings for ammonia, nitrites, ph, etc?

[leebca]

Depending of course on the copper concentration the fish were in, it could have a negative effect on them. If the store was using a low level copper, then they were more than likely not trying to cure anything, just trying to prevent any visual signs of the parasite to prospective buyers. Many LFSs do this in the hopes the fish will turnover before they succumb to problems.

On the other side of spectrum, if the copper level was high or if the LFS does not frequently monitor the concentration, the copper level could have gone into dangerous levels -- harmful to the fish.

Now add another parameter. If the copper used by the LFS was a 'poor' copper (un-chelated to typically chelated, which is most likely) this does have adverse effects on some fishes.

So any one or both of the last two paragraphs can actually be the cause of your fish's behavior. I have not kept these fish before so I can't say what their normal behavior is, nor have I ever treated them with copper to determine how tolerant they are to the copper. So the treatment could be the problem.

Now let's look at the salinity issue. It can be a problem too, unless the difference between your tank sp. gr. and the LFS sp. gr. is less than 0.004 sp. gr. units. If the span is greater, the fish could be reacting to a sudden change in sp. gr. You see, to change (go up) in sp. gr. by 0.004 units or more, requires a large amount of time for the fish to adjust. The time given during acclimation would be way too short of time for the fish to adjust to the new sp. gr.

So, there are a few different possibilities here, including 'normal' behavior. Sorry I can't help you any more than this.

[Lemonhead]

Thanks again to everyone for all your info.
Here are my tank readings. Ph- 8.2, Nitrite and Ammonia are 0, Nitrate-10; Alk-10; salinity- 1.025
I do not know the type of copper at the store. I do know that it is used to kill off any parasites that may be on the fish and the water is a blue color as well.
I NEVER dump the stores water into my tank. I acclimate with a slow drip for 2hrs and then net them out.
The owner of the store is in and out during the week as he sets up tanks and performs maintenance on systems. I know he has been doing this for many years and is very knowledgable so I do trust the input he has provided along the way.
My husband spoke to him today when he picked up RO about the gobies. He also asked all the water readings. He is not sure of this behavior either. If it continues I will have him come out and assess the situation. So far there are no red flags as to what is going on other than maybe stress.
Today I have not seen any darting at the sandbed.
All is normal with fish swimming and eating. Keep in mind my fish are very small for the most part. I had to store owner order them this size so I could watch them grow and enjoy them longer so tank space is not an issue at this point.
There has been no problem with the Flame Angel and the Coral Beauty. Infact they can be seen quiet freq just hanging out together.
I will keep all posted if I find the problem.