RCS dying, what am I doing wrong?

[ambchang]

I tried going through the RCS dying thread, but I do not have as much information around my water parameters.

What happened is, I bought 40 RCS, and they were doing great, shrimps flying all over the place, three berried shrimp.

Then one day, I moved the powerhead to the opposite side of the tank (against the outflow instead of with the outflow), changed my CO2 ladder to a diffuser, dosed some excel and some flourish, then I get 1 dead shrimp a day for 3 straight days. There is at least one berried shrimp left, still berried, and the colours of the shrimps are super red.

However, the males are no longer flying around the tank like they used to. The shrimps seemed to me more lethargic.

Also, CO2 levels may be slightly above optimal based on the drop checker.

What should I do? What is wrong?

Help would be great.

[deleted_user_7]

Sounds like co2 is slightly above optimal.

[mordalphus]

i'd have to say that lots of people have killed their shrimp with excel as well. I've never done so, since i just use bottled co2, but I personally know people who have.

[deleted_user_6]

Originally Posted by mordalphus

i'd have to say that lots of people have killed their shrimp with excel as well. I've never done so, since i just use bottled co2, but I personally know people who have.

+1 on this.. excel is toxic to inverts IME. I've killed a few RCS, ghost shrimp, and even an apple snail with excel dosing.

Is there some reason that you are using excel and CO2? Are you running DIY CO2, and trying to supplement?

I'd highly recommend going out and getting test kits so you can more accurately diagnose the problem(maybe PH & KH so you can get a ballpark of where your CO2 is at. Ammonia, Nitrates, as shrimp are sensitive to these).

[williamsonaaron]

Originally Posted by justlikeapill

sounds like co2 is slightly above optimal.

rofl...

[albirdy]

i didn't know about excel being a shrimpicide.

i was planning on supplementing my tank (pressurized) with flourish to rid of bba and other ish algae

[deleted_user_7]

I had a recent thread about shrimp and high tech tanks and excel was mentioned... Just as any people use it with shrimp and say it's fine as those who don't.

You said yourself that you fiddled with the co2, your drop checker says it's higher than optimal, so why suspect the excel? It's your co2.

[mordalphus]

I should mention, that when excel is used in recommended quantities (which for some reason is RARE), it may be safe for invertebrates. It's when it is used in double, triple and quadruple doses that people kill their animals.

[deleted_user_6]

Originally Posted by justlikeapill

I had a recent thread about shrimp and high tech tanks and excel was mentioned... Just as any people use it with shrimp and say it's fine as those who don't.

You said yourself that you fiddled with the co2, your drop checker says it's higher than optimal, so why suspect the excel? It's your co2.

I'd be careful with this sort of hearsay advice. I am not trying to be contrary, but this sort of stuff has been going around a lot on the forums lately, and it's not a very safe way to carry on.

There is not much doubt that excel is toxic to invertebrates. There have been freshwater studies that show that glutaraldehyde(which is what excel is) is toxic even to fish embryos, and invertebrate eggs...
http://www.glerl.noaa.gov/pubs/fullt...5/20050003.pdf

http://www.ncbi.nlm.nih.gov/pubmed/17702354

I personally wouldn't use excel in with any shrimp I cared about. I'd definitely get your CO2 in check too though. Like I said.. get some test kits.. figure out your water params, make sure they aren't choking on ammonia(and probably back down your CO2 a bit).

[Darkblade48]

Assuming that your CO2 drop checker is using a 4 dkH reference solution, and that you did not over dose Excel, then I would say that the problem lies with the CO2.

This is because you mentioned you switched from a ladder type diffuser to a glass/ceramic disc type diffuser. In addition, your CO2 drop checker may have provided some hints (though, what exactly is "slightly higher than optimal? How yellow was your drop checker?)

As people have mentioned, Excel can kill shrimp, if not dosed in the recommended amounts.

[ambchang]

I didn't over dose on Excel, I am using it as recommended.

If the problem is CO2, then I would remove one of the diffusers (I have two), and just let one of them run.

The drop checker is lime green, which is rated as either sufficient or above, depending on the water hardness. I guess I would get a kit and test that out to remove some of the confusion.

Thanks guys.

Also in the meantime, I will stop dosing excel, just to be safe.

[Darkblade48]

It sounds as if you are not using the drop checker correctly. Do you have a 4 dkH reference solution in there? CO2 is not dependent on water hardness, also...

Test kits for CO2 do not work, in general, as they erroneously rely on the kH/pH/CO2 relationship.

[DevonCloud]

+1 to getting a 4dkH solution and then checking your drop checker. Moving from the ladder to a diffuser can make a big difference in the total amount of CO2 dissolved into the water. Are there any fish in this setup? If so, are they showing any signs of distress?

[ambchang]

There are 6 rosy danios in the tank, along with 4 otos. They all seem to be doing fine as always.

[deleted_user_6]

Originally Posted by Darkblade48

It sounds as if you are not using the drop checker correctly. Do you have a 4 dkH reference solution in there? CO2 is not dependent on water hardness, also...

Test kits for CO2 do not work, in general, as they erroneously rely on the kH/pH/CO2 relationship.

Remember that the DC itself relies on the KH/PH relationship. The only difference is that we have a set concentration of carbonates. I don't think a drop checker is more accurate, it's just easier to get a ballpark idea at a glance.

I'd say that as long as you don't have something in the tank attributing heavily to a high KH, and a high/low PH(like a chemical PH modifier/regulator that breaks the pH/KH relationship), that the inaccuracy for both will be nearly the same. Neither method is really that accurate. People tend to have this misconception that a drop checker is the last word in CO2 measurement.
It think the best/simplest explanation of this was posted by DarkCobra.
http://www.plantedtank.net/forums/fe...ml#post1003610

Also, if you want to make your own 4dKH solution, here is a good post about it over at APC. That way you can get your DC working right.
http://www.aquaticplantcentral.com/f...tml#post333187

IME, fish also tend to be more sensitive to CO2 than shrimp. Every time I've had a go at turning the tank into seltzer water, the fish are always the first up at the surface gasping, while the shrimp are still cruising around at the bottom merrily. Again, this is just my experience, but if your fish aren't acting strange, then it is most likely not the CO2.