Sometimes inactive shrimp

[beanbag]

Hello folks,

 

I have a newly set up and cycled tank for about 2 weeks now.   The thing that concerns me is that sometimes one or more of my shrimp get inactive, and just park or camp out at a certain spot for a few hours or more.  When I see shrimp at the fish store, they seem to be always moving and grazing (picking with their little claws).  In my case, sometimes one or more of the shrimp will walk and swim around the tank for a while (but not graze), so it's not like they are inactive 100% of the time.  They seem to take turns being inactive.

Trying to come up with some possibilities here:

I wonder if the lack of grazing is because I have a new-ish tank and there isn't much biofilm or algae for them to pick at.  When I first put in a new object, e.g. marimo or cholla log, they pick at that for about a day, but after it gets picked clean they generally tend to ignore it.  I sometimes try to feed pellet shrimp food and sometimes they go for it and sometimes they totally ignore it.  (BTW, I tried today the jayc agar and chlorella recipe, and they totally ignored it)

Or do I need more moving water?  I have an under-water spray bar with a line of nozzles, but it is set up so that it only moves the water underneath the surface and doesn't make bubbles or waves.  Near the bar there is enough turbulence to makes leaves rustle gently, but the water movement at the far end is kind of slow.  Today I saw a shrimp tank that had two powerheads in it that sprayed with such force that the shrimp were hanging on for dear life, but they seemed to like it.

Maybe my filtering is too good?  I have a 1 um water filter as part of my mechanical filtration because in the earlier days of this tank, I saw lots of little floating bits, some of which were moving.  So I said "f_ it, nothing is going to get past my filter"

How much does lighting affect things?  I don't have a recurring light cycle.  I just turn on the light when I am around to look at it or while I am awake, and turn the light down to dim when I am away or sleeping.

Also one of my shrimp just molted today, so I assume that is the one being inert right now.  I saw in the discarded shell tiny bugs moving around, but I had just read on this site today about it happening to some cherry shrimp expert, and that it didn't seem to cause problems.

I am a bit paranoid because I recently had a cherry shrimp of a few weeks die on me.  It was sometimes inactive, then got really lethargic the last two days, then just died one day standing up.  (Maybe because that day the water temp got into the mid 80's, which didn't help)

 

*background info:

1 gal tank with pool sand and some small plants

2 Amano, 1 yellow, 1 blue shrimp

Ammonia 0, nitrite <0.1ppm, usually 0, nitrate usually 3-8 ppm

kH 4-5, gH 6 but then slowly rises up to about 8 until I start changing water

TDS ~200 for my RO remineralized water, usually rises to about 220-230 ppm in the tank.

recently I have been doing 10-20% water changes every 1-2 days due to the rising gH and TDS issue.

[jayc]

20 hours ago, beanbag said:

BTW, I tried today the jayc agar and chlorella recipe, and they totally ignored i

No way !!

something is seriously wrong with your shrimp to ignore that. 

How much water flow do you have? Give them a slower flow rate.

[beanbag]

maybe one gallon per minute or so?  Or in terms of water flow speed, maybe about 1/8th inch per second in some areas.