I want to ask that do I have to add carbon if I have these media? sub-pro, eheim mech, matrix and denitrate?

Also, do you have any comment about my media? should I change any of these?

The media you are using is fine as long as it does not raise tds,ph, etc....

Usually do not use carbon unless there is a problem in the tank and you want to remove any toxins, medications, tanins, etc...

THanks Chi. I leave a pack of carbon in my filter 5-6 months since I setup my new tank, it might be the reason of my current problem. Just change the carbon and leave it for a week to see if it's better :">

Hoang,

what is your problem that you mention?

Don't forget, carbon has a limited life span of effectiveness.

Once the carbon has absorbed impurities in the water and is "full", it will stop absorbing chemicals and just become a biological filter media.

Actually I have heard that carbon will start leeching back out the toxins etc...once it is full and can no longer absorb impurities.

Really? I thought that it will release toxin back to the water??? I am thinking of using purigen instead of carbon

My problem recently not solve, I still looking for the reason of my mystery death and it's around 2 month already :(. I found death everyday and even see they are dying (color fade and not run away when I touched with my net, only moving very slow then die).

You really should have cleaned out that old carbon sooner Hoang and replaced it with new! Also may be a good idea to clean out the filter/media with another tanks old water (one that does not have a problem).

I toke that carbon and replace with the new carbon already. I have to clean the media also? what about the bacteria inside if I clean it?

Not sure about Activated Carbon leeching and releasing toxins back into the water column.

But if you wash your filter media in old tank water, not tap water, then most of the bacteria will remain.

I toke that carbon and replace with the new carbon already. I have to clean the media also? what about the bacteria inside if I clean it?

As jayc said as long as you use old tank water, use your other tank's water when you doing water change then the bacteria should be fine.

Because the other tank is just a nano, might not enough water to clean the filter media, can I use the current water in my 3ft tank to clean the media?

You can.

Are you using RO water or tap water to refill the tank?

I am using RO water with salty shrimp mineral. There are a lot death (~10) since I changed the carbon on last Sunday. Are they poisoning?

This doesn't sound like a filter problem anymore.

You'll need to start sharing your water parameters with us.

Do you have a TDS pen to measure TDS?

Nano tanks are susceptible to nitrate spikes. Even if your nitrates are <20 now, due to WC, filter clean etc... A spike can cause continued deaths weeks after the event.... Nano tanks do new much more attention with WC and filter clean.

Nano tanks are susceptible to nitrate spikes.

It's his 3 footer that has a problem. Hoang has another nano tank, but that isn't the problem.

I test my water last week and everything right. Tds is around 150, ammo 0, nitri 0, nitrate 0, Ec pen 300. Gonna check again when I come home and post

This is my current WP

PH ~6.4

NH3 0

No2 0

No3 0

TDS 160

EC 300

KH 1

GH 5

Can't see anything wrong there.

Do shrimp get diseases?

I'm sure you covered these but im not sure what thread its in so i apologise in advance:

You havent had anything that could possibly have produced fumes around the house? ie Pest control, paint, air freshener, deodorant, perfume, cleaning agent (my mum once put one of those plug-in air fresheners right next to the air pump- byebye fish tank!)

Do you use RO water re-constituted or tap water conditioned?

Start going through your mind again on what you add to the tank.

Food - what type?

Fertilisers - What ferts?

CO2 - how much? Is this on overnight? Are the deaths only occurring at night? Are you using liquid carbon?

O2 - is there enough surface agitation and water circulation to maintain Oxygen levels?

Heat - is the heater working properly? ie. overheating or dead.

New inhabitants - did you introduce any new shrimp to the tank that might have carried diseases?

Heavy metal poisoning - unlikely, I know, if you are using RO water. But get an LFS to check for copper, magnesium and calcium levels, if you don't have test kits of your own.

Death occur any time, their color is fade, inactive and die. I think the reason should be the active carbon which has been used 5-6 month ago and haven't been changed. It release the toxic back to water and make shrimps poison and die.

I replaced the old carbon with the new one and leave it until purigen and matrix came so I will replace that carbon also.

I didnt know that we are not using active carbon in the shrimp tanks >"<

It wont be the air since I am using 1 air pump for both nano and 3ft tanks, I also use the same food for both, not using Co2, plenty water flow and surface for O2.

Death occur any time' date=' their color is fade, inactive and die. I think the reason should be the active carbon which has been used 5-6 month ago and haven't been changed. It release the toxic back to water and make shrimps poison and die.

I replaced the old carbon with the new one and leave it until purigen and matrix came so I will replace that carbon also.

I didnt know that we are not using active carbon in the shrimp tanks >"<

It wont be the air since I am using 1 air pump for both nano and 3ft tanks, I also use the same food for both, not using Co2, plenty water flow and surface for O2.[/quote']

Hopefully that's it. Let's monitor and see if the new carbon has any effect.

Alternatively, you could try Mosura Tonic Pro. It has Beta Glucan in it that helps the shrimp's immune system to fight bacterial infections. I even feed my fish Tonic Pro. It's a great product that can help those mysterious deaths when water parameters all seem fine.

This is where we have to consider bacterial infection/disease where the shrimp slowly die off, I know many have experienced this including me. It is usually when adding too many shrimp from different people to a single tank. The sad truth is nothing much can be done except carbon, uv, water changes etc. I have read some use medications like paraguard on other forums. Whole tanks could die off, you may see no shrimp deaths for couple weeks and then few more will die until nothing is left. I don't mean to scare you but this is the truth. Hope it gets better soon.

so what is the answer if say all the shrimp die and you want to start again. Do you have to decommission that tank ,throw away all your substrate or can you just clean the substrate and do a total water change clean filters etc recycle tank and start again. It is something I have never seen written anywhere so is an interesting point for any one who may have this problem