Cherry shrimps dead!!

[uklau]

Hi, I have a dozen of healthy shrimps in my 1 feet tank for the past 3 months. Over the weekend, I've decided to tear down the tank (having only gravel & without any fertilizer) & replace the gravel with Seachem Flourite.

I siphoned the water out to a temporary container & net the shrimps out. After replacing the gravel with Seachem Flourite (completely washed), I siphoned back the water from the temporary container & move the shrimp to the new tank. The shrimps didn't look happy (i guess it could be due to the cloudy water) & this morning, all were dead

Can someone advise what could have gone wrong? I guess I've murdered all my shrimps

[Jeanxavier]

It could be due to the sudden change in water parameters - I am not familiar if Seachem flourite contains any extra minerals thus causing pH swing etc.

By replacing the gravel also means removing most of the beneficial bateria in your tank apart from your filter (correct me if I am wrong) and thus there may be a need to cycle your tank before placing the shrimps back.

[uklau]

Thanks for sharing your thoughts, Jon. I believe lack of beneficial bacterial is not a main factor that causes dead in my tank. I was re-using the age water & filter media remains unchanged. NH4 or NO2 will not spike in such a short period. pH remains the same, +-0.2. FYI, the shrimps are not eating much.
Not sure if it could be due to adding a fossil stone (that's something new after the makeover, apart from flourite). I've soaked the fossil stone for a day & wash thoroughly. What else could be wrong?

[kemp]

uklau, did you added any new plants into your new tank? I've similar experience with plants being added to my tank, and it totally wiped out my shrimps and i found out that it's because the plants contain some pesticide on it and i didn't do a thorough cleaning to remove them.

[diki]

Even if you use back the age water, changing of gravel does make some significant changes to the water, even if you wanted the gravels properly. Some resident chemicals would slowly leech out. Actually I still think need to cycle the tank for a while first before putting back the shrimps. I would say changing gravel is not a small change in the tank.

[Neon Shrimp]

I agree with diki that it was the Flourite. It is very difficult to wash and it also causes pH shift! Sorry about your shrimp

[Quixotic]

As far as I know, Flourite does not have pH changing properties. Plus, there are accounts of aquarists out there who do not experience shrimp deaths with Flourite.

But Flourite is a rich substrate. So there may be some properties that are introduced in to the water column. FWIW, the water would be very cloudy initially and I think the oxygen level may be low. I have used it previously in my set up and I always run an airstone during the initial stage.

Any major changes will bound to affect the shrimps. I do agree with diki that it may be better to still cycle the tank before adding the shrimps back.

P.S: FWIW = For what it's worth

[uklau]

Kemp, I did add Anubias nana but it was from my other planted tank. It has been there for the past 1 month & all my fishes, ghost shrimp & snails are doing well. I'll take note of your point when adding new plants. Thanks. By the way, how do you tell that your plants contain pesticides?