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Tam

Help with new IAVs system in Vietnam

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Dear all, 

I had started new IAVS system.

Fish tank is 800l, plant area tank is 400l, I had 3 system like that

I use the silicate sand,

After 3 days after I add fishs in tank, fish still have die - 1 fish die / day/ tank.

Every tank I add 40 fish/tank; 6g/1 fish; I feed fish with 6g of fish feed/ tank

Now in tank1 have 3 fish die, tank2 have 3 fish die, tank3 have 2 fish die.

I make test with water today, with all information like: NO2 0,1 mg/l;  NO3 1-->10mg/l;  SiO2 3mg/l; PH 7,8; O2 8mg/l

I think I not washing sand enough before, so SiO2 so high, it make fish die

 

Please help me, is this the cause, how I can determine this 

 

Thank,

Tam

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Hi Ande,

I waiting for some advice,

My fish  was continuing have death, 

After I replace a half of water, check SiO2 again, it still 3 mg/l,

Please see picture below for clearly observe

I don't know what I will do?

I would like to receive your help.

Thank!

Tam

fish die 190815.jpg

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Hi Tam, Fish kills are a tragedy.. seen similar fish deaths in many new systems.  Do not necessarily mean it is due to SiO2.. it could be the weak and stressed ones dying out.  What temperature are you at?  Do you have more turbidity due to the Silica dust?

If it is not a lot, once essential microbes are established, the fish deaths rarely happen.  What have you done to jump start the nitrification process?

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Hi Tam,

I do not feel the SiO2 is a major issue here.
I believe the culprit of your issues is NTS (as I call it)... New Tank Syndrome... and this is why I believe this to be the case:

You added fish in just 3 days.
Even if you did jump start the "N" cycle... and even if your water is 32C, the nitrosomonas and nitrobactors would still require 8+ days to cycle from NH3/20mg NO2/50 NO3/150 to being a safe, cultured bacteria colony.

I note you did not supply ammonia readings.
Being the initiating and most toxic water parameter of the nitrogen cycle, in my view, is the highest needed water test and ought be essential in your test kit bag.

Being in Vietnam, I assume your water temps are very warm this time of year... perhaps 26-30 Celsius.
You also state a pH of 7.8 and O2 of 8mg/l

Ammonia presents itself in 3 different forms, according to the pH.
At 7.8pH, ammonia presents as NH3-N, the most toxic form.
Additionally, and unfortunately, the toxicity of NH3-N increases exponentially as the water temps rise above 20C.

New, un-established bacteria are more susceptible to NH3-N toxicity than many fish...
Thus, the system/s are in bio-overload from week #1.

Mortality due to "N" cycle & NH3-N has several very common, visual signs.

Due to burning from MH3-N, visual signs can be as minor fraying of some or one of the fins .. though to severe bleeding into the rays, skin, gills and eyes.
Additionally - all external soft tissues, mucus membranes, eyes, gills and anus may show the same degree of visual variance, from mild burning to severe cellular bleeding.

Also additionally - NH3-N mortality in established bio-systems presents slightly differently than it does in newly setup systems.
In established aquaculture systems, NH3-N moralities effect a very high % of the total stock, it does so very rapidly... and all carcasses present with equal visual appearance.
In new systems, the week and stressed get burnt - the healthier show resistance.... after a day or three has passed, those initial week burnt fish now have visual bleeding, burning swelling, fungus and bacterial issues... while those fish with initial resistance now begin to succumb and initial burning and bleeding begins.

Thus within 5-10 days you can have a situation where moralities present in many different manners, and different stages of toxicity exposure... exactly like you photo.
Some (most ?) fish appear to have very little visual signs (visually non-advanced), where as the main fish in picture shows every sign I have mentioned (visually highly advanced).

So, what is a suggested avenue of mitigation ?

1. Water changes only reduce the concentration - not the toxicity.
You need to lower the toxicity levels by lowering your pH closer to 7.0, and continue water changes.

2. As counter productive as it may sound, the addition of salt to the level of 2-3mg/l has huge benefits... far too many to add to this response. (search this forum)

3. STOP FEEDING THE FISH FOR 4 DAYS !!!
Mortality during this period is 100% NOT due to starvation... it is 100% due to everything I have mentioned thus far.

4. Do Not Feed the Fish !
Correct - do not feed the fish until moralities stop. (especially for new systems)
In an uncycled system, feeding your fish when the water is already toxic is equal to adding petrol to a fire.

Sorry I didnt have more time to be more detailed in my response.

Cheers
Toga

fish.jpg

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Hi Tam

When replying to posts, you do not use the report post button. That's for reporting spam abuse etc. , and can only be seen or read by moderators.

I will copy your responses  (in the 2 reports) to vkn & Toga here:

Tam

Submitted  5 hours ago

Dear VKN,

What temperature are you at?  Do you have more turbidity due to the Silica dust?

The temperature is 30 Celsius. I don't see turbidity from silicate dust so much.

If it is not a lot, once essential microbes are established, the fish deaths rarely happen.  What have you done to jump start the nitrification process?

image.thumb.png.4c8b1f5ac22d7bb7018ab5025dfa8eda.png

This picture show the way I used to raise bacteria. I use feed as source of ammoniac, bacteria I add in flour form.

I add fish after nitrogen cycle is ok (nitrite is slow down 0.1; nitrate has increased more than 40 mg/l) on 7-Aug,

Thank for your advice!

 

Tam

Submitted  4 hours ago

Dear Toga,

Thank for your help,

Tomorrow I will follow your instruction,

I will change water, add salt batch for cure fish, stop feeding,

image.thumb.png.920c1e11372e1c8c3a46d3548ff4499c.png

As I post to reply report to Vkn,

I had create the nitrogen cycle before adding fish on 7-Aug,

I willing to hear your help on my beginning small system,

 

Thank

Tam

 

 

cheers

 

 

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Hi Tam,

Good work keeping records, they are key to good success when you understand them well.
Take time to study, understand, compare seasons, success and failures of your records.

I note you have NH4 record as well as NO2/3.
Due to the very low readings in your results, and the short time period from setup, suggests to me that your total "N" cycle is very shallow, very low... meaning the bacteria culture is very small and not very strong.
The cycle values that I indicated above, are perhaps higher than what is actually required to establish healthy strong bacteria.
Below is a quick google image of what I mean. Take your records and make a similar chart and compare them... Do you see the difference ? Can you see what I refer to as being a "very shallow cycle" from your records ?

I note you make reference to "Tank 1", "Tank 2" and "Tank 3".
Are these 3 tanks joined together to the same grow bed/s ? ... OR
Are they 3 separated tanks each with their own separated grow beds ?

The answer to the above is important to many questions about future management... but it is also unimportant to my next point of note:
Disease Mitigation - (This is why adding salt is good - search this forum)
Toxic water, No/low/unhealthy bacteria, burnt/sick/dying fish, very high water temps...
All of these dramatically increase a) Disease Potential, b) Disease Verility and c) Disease Transmission

Maintaining farm hygiene is paramount.
- Sterilize your nets (soak in very strong salt water works OK) **EDIT** Followed by drying in the sun
- Wash hands and arms when working in different tanks
- Do not transfer anything between the tanks or grow beds
- Remove and dispose of mortalities immediately and regularly

One last comment for this response -
I note your pH has risen since you started.
a) What is the pH of your source water before you add it to your fish tanks ?
b) Where is this source water from ? (ie: A dam, river, well, bore, city tap water, collected rain water)
c) Do you store your water before use ? and if so - What is the material of the container ? (ie: plastic, concrete, earth dam, rubber liner)
c) Did you pH test your sand before purchase/use ?

Cheers
Toga

images.png

Edited by Toga
Added info (see edit history)

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Hi Toga,

Are they 3 separated tanks each with their own separated grow beds ?

Yes, they are

Do not transfer anything between the tanks or grow beds

I used only one net for three tanks.

Maintaining farm hygiene is paramount.

Thank for your advice I had never done any hygiene 
- Sterilize your nets (soak in very strong salt water works OK) 

The best way when using net for all three tank
I note your pH has risen since you started.
a) What is the pH of your source water before you add it to your fish tanks ?
b) Where is this source water from ? (ie: A dam, river, well, bore, city tap water, collected rain water)
c) Do you store your water before use ? and if so - What is the material of the container ? (ie: plastic, concrete, earth dam, rubber liner)
c) Did you pH test your sand before purchase/use ?

a) PH is 7.8 before I add it to my fish tank

b) Well in ground (used to water plant, plant was grown in soil), collect water from rain

c) No. I just pump the water from well to every tank

d) I did not test PH of sand

I have just test it, PH is 7.4

Disease Mitigation - (This is why adding salt is good - search this forum)

Can you help me find position of adding salt way? I can not find it

 

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It’s all good advice above and it's all true in a fish-focused aquacultural systems.
  
However, I wouldn't do salt bath during start-up phase for several important reasons nor I would suggest water changes while your system maturation.  The secret is in the microbes.  We are working with a living system that regulates by itself.  Microbes evolve along with the plants they sustain/interact with, meaning they too benefit from chemical levels, pH, temperature and other conditions to keep its life going.

I would have started with small fish numbers or much smaller healthy fish for starters.  Your starter fish looks much bigger to me.  What about your plants?

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Hi Tam and VKN,

To add further clarity, freshwater nitrification bacteria have a much higher tolerance to salt than almost every species of fresh water fish and most disease bacteria.

7-9% Salinity levels are used in waste water treatment plants with zero adverse effect on the nitrification bacteria (microbe) life cycle.
However, at 9% salinity, they are much less effective at nitrification.

**EDIT Regarding Salinity**
9% Salinity = 90,000mg/l
Remedial Recommendations of 2-3mg/l = 0.0002% - 0.0003% salinity

Yes, salinity levels can and do influence plant growth immensely.
Some plants simply die @2mg/l, others tolerate it but grow very poorly.. most fruiting plants hate salt.

It is my view that if you do nothing and do not intervene with some sort of mitigation process, your stock losses may be significant.

Have mortality rates decreased since you started water changes ?

Cheers
Toga

Edited by Toga
Added info (see edit history)

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Dear Vkn,

I would have started with small fish numbers or much smaller healthy fish for starters.  Your starter fish looks much bigger to me.  What about your plants?

I bought fish with 6g/ individual.

With my plant, I plant 4 tomato/ 1m2, , plant seem deficient nutrient (as picture I attach), 11 days after I plant in grow bed

image.thumb.png.b8333476f1f5f2d15f04f354dadb144c.png

 

Dear Toga,

9% Salinity = 90,000mg/l

I follow your advice, with add 2g/ 800l of each tank today

Have mortality rates decreased since you started water changes ?

The rate of mortality continue increase,

image.thumb.png.32af66b252d0fa38f15731c6f04ff247.png

image.png.c8096057786a14a94ac1c6e130d929db.png

As you see my record, the mortality continue increase, 

Even I stop feed fish, the belly of fish so big, some fish have different swimming pattern, sign of deficient of oxy,

Hope adding salt can help fish stop die,

Thank all,

Tam

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Each one of us will do things a bit differently than other people.  Prevention is always better/easier than cure.

In addition to what is discussed, quick changes in temperature during transfer could be another reason for these fish kills.   I now suspect parasitic infection that spreads fast but I could be wrong.  Stressed fish are more susceptible to parasites.  Improper transportation and/or unhygienic handling at nursery may at times lead to 100% mortalities.  For parasitic infections, there are several chemicals that are applied by aquaculturists by bath, such as salt, formalin, H2O2 and KMnO4.  If possible, first see if you can get the fish tested at a lab.

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Hi Toga,

Thank for your help, 

Today, my morality issues stop, do not have any fish die 

I had feed them, them seem so hungry after 4 days don't eat any thing

I will add more fish tomorrow, 

With my tomato, it have some bug, 

See picture for more detail,

Can you advice me some way?

How can I use for kill them?

image.thumb.png.eda792123a714c2ba977cf5fc5ca0c93.png

 

Thank!

Tam

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