# Other Aquarium Forums > Freshwater Fauna > Invertebrates >  cooked shrimps

## Irn-Bru

found another cooked Malayan shrimp (turned red) at the bottom of my tank a couple of days ago...

checked with NA, suggested that the temperature could be too high... possibly as i'm using 2x16W compact for a 1.25ft tank... lights are about 1 inch from the water surface then... coz it seems to give more bubbling from the plants...

Chan says his recommendation is 3 inches from the water surface... would like to hear if you guys follow such a rule...

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## Irn-Bru

found another cooked Malayan shrimp (turned red) at the bottom of my tank a couple of days ago...

checked with NA, suggested that the temperature could be too high... possibly as i'm using 2x16W compact for a 1.25ft tank... lights are about 1 inch from the water surface then... coz it seems to give more bubbling from the plants...

Chan says his recommendation is 3 inches from the water surface... would like to hear if you guys follow such a rule...

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## Irn-Bru

found another cooked Malayan shrimp (turned red) at the bottom of my tank a couple of days ago...

checked with NA, suggested that the temperature could be too high... possibly as i'm using 2x16W compact for a 1.25ft tank... lights are about 1 inch from the water surface then... coz it seems to give more bubbling from the plants...

Chan says his recommendation is 3 inches from the water surface... would like to hear if you guys follow such a rule...

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## Irn-Bru

found another cooked Malayan shrimp (turned red) at the bottom of my tank a couple of days ago...

checked with NA, suggested that the temperature could be too high... possibly as i'm using 2x16W compact for a 1.25ft tank... lights are about 1 inch from the water surface then... coz it seems to give more bubbling from the plants...

Chan says his recommendation is 3 inches from the water surface... would like to hear if you guys follow such a rule...

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## sherchoo

Best if you actually know the temp instead of guessing. 

Can give more info as in filtration, , water chemistry, planted, co2, fert, tankmates etc.

Quite hard to know what's going on without background info.

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## Irn-Bru

will look for a small thermometer tomorrow...
sorry, no gadgets to test the water chemistry... don't understand them entirely anyway...  :Smile: 

just like to know about the 3 inch rule recommended by Chan...

thanks

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## tawauboy

don't think there is any rule governing the spacing between light and water surface. when the light is very near the water surface, you will heat up the water. having a bigger gap will reduce the heat transfered to water.

maybe the 3' recommendation from chan is based on his experience. if you do not wish to increase the gap and having a high temperature problem, you should consider getting a fan.

you can do a quick check of your tank water temperature by using you hand. if the water feels warm, then the temperature could be &amp;gt;30deg. if it feels cool, then the temperature could be around 28deg.

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## apollo

Not sure if warm water is the cause. But all shrimp when dead turns red. So cud it be other reasons for your dead shrimps?

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## Irn-Bru

oh i see... that's interesting...
so i guess its still best to gather the various statistics in order to know more...

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## sherchoo

Maybe you should check your pH and kH first. From there you can check if it's due to co2 poisoning. If you have a NO3 test kist, it would be a plus.

Also provide us with other info like lighting (amount &amp;amp; duration), co2 (method &amp;amp; duration), tank inhabitants, heavily planted or not, ferterlization, etc.

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## Cardinal Tetra

ammonia posioning?

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## sherchoo

> ----------------
> On 11/20/2002 10:46:38 PM 
> 
> ammonia posioning?
> ----------------


It's quite hard to tell what's wrong without information. That's why we should investigate what's wrong with at least some basic info to at least make an educated guess.

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## Irn-Bru

ok, here goes:

Tank Size (WDH in cm) - 39 X 22 X 27
Volume - 28litres
Lighting - 2 X 16W Osram Dulux EL Daylight (9 hours daily, just increase from 8 hours yesterday)
CO2 - Pressurised tank at 1 bubble every 3 seconds or 0.3bps (9 hours daily)
Filtration - Eheim Liberty 100 (set to minimum, never wash filter)
Subtrate - Normal gravel from NA with a thin layer of Jaqno Flora Base (40g) in between
Water Change - 30% to 40% weekly
Temperature - No thermometer but tank is kept in aircon office
Fishes - Leopard Cory (2), Otocinclus (2), Platty (1), Siamese Algae Eater (4), Malayan Shrimp (1), Cherry Red Shrimp (11)
Plants - Mopani wood, Nymphea lotus, Elatine tiandra, Riccia fluitan (floating), not sure about others...


As for water chemistry, I finally opened my expensive Tetratest kit, did a test after changing water just now. Might not be doing it correctly, but here's what I have:
pH - 6.8
KH - 6
GH - &amp;lt;3
NO3 - light brown, can assume zero?
NO2 - light brown, can assume zero?

My Tank

any other info required? many thanks!

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## PeterGwee

From the results you get, I cannot really say its CO2 overdose but the level is slightly on the high side. 28ppm is to me on the high side but I think Bclee has 30-35ppm for his tank and with no troubles except for introduction of shrimps? Maybe you can try cutting back on CO2 to reach a pH of 7 to see if it helps. Other question, does your office's aircon go &amp;quot;off&amp;quot; after office hrs? If it does, then probably the large temperature swing affects the shrimps faster than the fishes.

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## Irn-Bru

sorry but where do you get this 28ppm from?

the current CO2 level is already at its lowest using an electric regulator, any lower and i will have problem regulating it...

yes, my office aircon goes off at night... but maybe the high temperature could be because i was putting the lights within 1 inch of the water surface before? i am putting them 3 inches away now...

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## PeterGwee

Maybe you can do some reading at http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm
Hope this clears up your CO2 level doubts...and yes the when air-con if &amp;quot;off&amp;quot; the change in temperature of the tank water could cause much harm to your fish and shrimps. Maybe you can invest in a thermometer to check the temperature of your tank when aircon is &amp;quot;on&amp;quot; and temperature in the morning when aircon is still &amp;quot;off&amp;quot;?

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## Allen_1971

> ----------------
> the change in temperature of the tank water could cause much harm to your fish and shrimps. 
> ----------------


Peter,

could you explain where you are coming from with your comment? i.e. in what way would a change of temperature cause much harm?

Irn-bru,

One simple way to check if your CO2 levels are ok is to switch off your CO2 injection for a day, and then measure your PH level (in other words, your ph with just ambient co2 dissolved). After that, simply switch on your injection and target for a 0.6 drop in your ph... that will typically give you approx 15ppm co2 dissolved.

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## PeterGwee

Allen, Irn-Bru mention that the aircon is &amp;quot;off&amp;quot; during the night which would cause the temperature of the tank to rise even if the lightings are &amp;quot;off&amp;quot; (suppose the tank temperature with air-con is 22-25 degrees and once the aircon is &amp;quot;off&amp;quot;..temperature would slowly creep up to normal ambient temperature. This constant change of temperature would affect the creatures in the tank.)

Regarding your point that drop in 0.6 of pH reading would give you a CO2 level of 15ppm...I beg to differ though. Example with no CO2 injection my pH is 8 and KH is say 3 which will give me 0.9ppm of CO2. With your theory that drop in 0.6 of pH will give you 15ppm? (pH 7.4 and KH 3 = 3.5ppm of CO2 only?)  :Evil:

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## Allen_1971

Oh I see what you mean about the temperature... yes the varying temperature could be unsettling for the fish as stability of the environment is always nice... How much it actually affects the fish I'm not sure. But I see your point.

As for my drop of 0.6ph being wrong, I think I need to explain. You calculated again your co2 level basing upon the calculator. and yes based on the calculator a PH of 8 and KH of 3 will imply a CO2 level of 0.9ppm. The one mistake I did make is that it is 0.5 drop and not 0.6. a drop of 0.6 in ph will give you a higher level of roughly 19ppm.

Now I'm basing my assumption on this... the level of CO2 dissolved in water at ambient conditions, is 5ppm. Ignore PH ignore KH... not 0.9ppm (This is where the basic assumptions of the calculator again can introduce problems). Now if we look at the charts for CO2/PH/KH (which are based on the same formula as the calculator), you will see that regardless of your KH, a drop of 0.5ph from your ph level at ambient conditions will result in a CO2 level of roughly 15-16ppm. The only difference is that this method doesn't try to assume your starting point... you can go to this link for some CO2 charts

http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html

For example, my initial kh is 4 and ph is 7.4 my CO2 is 5ppm. If I drop my ph to 6.9, my CO2 goes to 15ppm.

If you juggle about the formula used, you will find that for a PH of X and a KH of Y that gives a CO2 level of 5ppm, then a PH of X-0.5 and KH of Y will always give CO2 of roughly 15ppm (roughly).

The first time I read about this I was really puzzled... could the mystery of good CO2 injection be as simple as a 0.5-0.6PH drop? surely not... then again the writer was the well known karen randell (if memory serves me). so I did some playing around, and basically it looks right.

Having said all this, I'm no expert in mathematics or science... perhaps my own assumptions are wrong... if such is the case, then so be it... live and learn!

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## Irn-Bru

sigh, another one bites the dust...
i am all clear of Malayan shrimps now...
wonder will my cherry shrimps be next...

allen, will stopping my CO2 injection for a full day kill my plants?

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## Irn-Bru

wahlau... just found a dried-up SAE outside my tank...
and this is already the second time...

dunno if the problem is related to my cooked shrimps...

anyway, are SAEs known to jump out of tanks? or is my tank temperature/condition that bad that they were forced to jump out???

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## loupgarou

things don't jump out due to temperature (hardly)

its because they can't breath that they jump out. so test for ammonia, nitrite, and maybe other toxic substances. (if you have lotus. check plant roots, could be hydrogen sulphide.)

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## Irn-Bru

if they can't breathe.. i should be seeing them at the water surface yeah? that's not the case...

my lotus is planted on the gravel... can't see the roots... but the plants seems to be doing well.. bubbling and all...

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## PeterGwee

May I know what test kit are you using? Maybe you should stop CO2 injection for the moment to be safe and get an air pump for your tank just to drive off the excess CO2..(could be CO2 poisoning)...It might even be NO2, NO3 or even ammonia problem which require you to do water change.

Best solution now is to do 25-30% water change, stop CO2 injection and add an air pump to remedy the thing for the moment.

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## Irn-Bru

i am using Tetratest 5 in 1 test strips...
results were posted early in this thread...

have stopped my CO2 injection and added an airpump...
water changes are done on Mondays regularly and even yesterday morning as well... don't think i'll do one for now...

but how will my above actions affect my plants?

i have lifted my lights to about 5 inches above the water surface to cut down the temperature and put in plastic covers on top of the tank as temporary measures...

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## PeterGwee

Remove the plastic covers for ventilation...it gonna trap more heat you know..In my opinion the 5 in 1 tetra test kit is not really recommended (Get all sorts of weird readings) get a pH test pen if you can afford it and other individual kits (much more accurate and safe in my experience). Temperature is not really of much concern here as I had tank water temperature up to 33 degrees last time and no apparent harm to both shrimps and fishes. (Please do a water change as I had doubts about your ammonia, nitrite and nitrate levels...all are deadly you know...don't be lazy!!) And last...not much harm to the plants as long as it is not for 3 days and more..

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## PeterGwee

Oh...forgot about your temperature shifts which may occur with aircon being &amp;quot;off&amp;quot;....okay..you can do away with the water change for now...best is to get a heater...set it to 28 degrees..should solve the problem I think...might be the shock cause by temperature shifts everyday...(that's my guess...hope that helps)

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## Irn-Bru

not lazy lah... but in office mah... a bit difficult to do so now lah... but the last water change was only yesterday leh... it should have cleared off whatever &amp;quot;poison&amp;quot; there is right?

arrgghh!! the tetra kit cost me $29 from aquamart and u say its not recommended??!! what brand do you have in mind for the pH test pen?

get a heater? thought my temperature is too high right? can the heater lower my temperature if its too high? and what's more... my tank is only 1.25ft long... adding a heater will totally spoil my landscaping... not that its very nice in the first place lah...

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## Allen_1971

Your plants should be ok... I don't expect them to suddenly wilt. However, if your SAEs are jumping out, I would say that there is something really wrong. I've never had an SAE jump out of my tank... they tend to be pretty hardy... lemme think a bit... maybe some of the other &amp;quot;pros&amp;quot; got ideas? Simon? DEA?

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## PeterGwee

Irn-Bru...you mention your Office is air-conditioned.. at what temperature is your air-con set to? Don't tell me its only 28 degrees? I think most are at least 25 and below?...Changes to temperature when air-con is off could make your creatures uneasy...Imagine I tell you to bath in water of 22 degrees...then ask you to jump into another pool at 33 degrees..repeatly over several days..sure you get sick mah. But really depends on how large temperature change..I need to know the difference...YOur tank lights are off before the air-con is off? Oh..almost forgot..any anti-chloramine solution to tank during water change? You never know whether the tap water in your office contains any chloramine or not leh...better to be safe than sorry.

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## Irn-Bru

the air-con is centralised, so dunno what temperature... but its actually kinda cold in here... everybody's wearing jackets and sweaters...

yes tank lights are off at 5pm before the air-con is off at around 7pm...

sigh.. will go get a thermometer on Monday lah... can't scrimp anymore liao...

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## Allen_1971

I'm taking a look at your parameters again...

39x22x27 = 23.166L max not 28 like you said and then you still have to minus your wood, gravel etc... sp lets assume 20L = approx 5G

ok you have 32W of light meaning... you have a whopping 6.4W/G thats really bright... considering you have office lights as well. Do you have lots of riccia floating or just a little bit?

I'll assume your CO2 is ok for now since no fish hanging beneath the surface.

Can you check what your flow rate is for the filter? i.e. how many L/hour? too high a flow rate may be stressful on your fish.

How thick is your substrate with ferts? Remember this will reduce the actual amount of water even more.

Water change can't be faulted, though one wonder if you stir up lots of dirt when you refill....

Temperature may be a concern, but I'm not sure... no experience keeping tank in office.

Your fish load hmmm depends on how big your SAE are? mebbe you could post a pic? 

The other parameters have no glaring problems... I just think you should cut down on the lights a bit... though it does matter how your lights are mounted (i.e. how far)

ok thats my 2cents for now

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## benny

> ----------------
> On 11/22/2002 5:13:07 PM 
> 
> ......Maybe you should stop CO2 injection for the moment to be safe and get an air pump for your tank just to drive off the excess CO2..(could be CO2 poisoning)...
> 
> ----------------


A cheaper alternative is to position a rain bar near the water surface to drive out the CO2. Isn't it?

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## Allen_1971

I still don't think its CO2 poisoning... no signs of that. The fish seem happy and thats a good indicator.

Actually I was wondering, do your lights go on and off during the weekend as well? and is your office pretty dark? i.e. do they switch off all the lights?

I'm thinking that besides the temperature issue... there could be one with lights... imagine being in pitch darkness. and then suddenly 'click' timer activates and suddenly your 32W comes blasting in... heck I know I sometime jump out of bed when my wife accidently turned on the ceiling lights when I'm sleeping... mebbe thats what scared your SAE? This is more true if your office is totally enclosed... no windows means no ambient light.

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## DEA

don't assume your no3/no2 are zero
what does the chart say?
first off, i'd advise a 30% water change for 3 days in a row
this should take care of it
my suspicion is no2 spikes
also, when was the last time you did a water change? N isn't the end all and be all
i'm sure there're plenty of metabolic byproducts which linger in the water
we'd have to do a DOC test to find out

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## Irn-Bru

allen,

i have already taken into account the gravel (about 1.5inch average), though not my big log... so water volume should still be 23L or say 6G. think 28L was a typo.

no, not alot of riccia floating... only filling 1/8th of the surface... but i've just removed them to another 1ft yesterday...

yes, CO2 seems to be okay to me too... if not all of them will suffer the same fate right?

how do you calculate the flow rate? anyway, my flow rate is the slowest, in fact... there's almost no surface turbulence at all...

water change is done by pouring onto the top of my wood, it minimises direct impact on my subtrate... used to pour it onto a piece of styrofoam...

my SAEs are adolescents only... probably the smallest that you can find in LFS here...

lights could be the problem... so far i have moved it further up... about 5 inches away from the water surface...

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## Irn-Bru

benny,

rain bar is too big for my 1.25ft tank... besides i'm using a hangon filter... abit troublesome yeah?

i've used separate air-pump to drive-off excess CO2 at the moment...

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## Irn-Bru

> ----------------
> On 11/23/2002 9:26:10 PM 
> 
> don't assume your no3/no2 are zero
> what does the chart say?
> first off, i'd advise a 30% water change for 3 days in a row
> this should take care of it
> my suspicion is no2 spikes
> also, when was the last time you did a water change? N isn't the end all and be all
> ...


DEA

i have some dirty brown colour on my results but the chart has no such colours for me to match at all...

30% water change for 3 days in a row? can't do so... unless i go all the way back on saturday and sunday lah...

what's a DOC test? how do i do it for my tank?

thanks

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## Allen_1971

the flow rate for the filter is usually specified by the filter maker... if you have the original packing, its probably stated on the box somewhere... if not, you can try searching their webby for the info.

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## sherchoo

I'm still curious what is the temp of your tank. If ppl in the office are wearing jackets/sweaters, I'm guessing it's as low as 21~22 deg.

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## Irn-Bru

> ----------------
> On 11/24/2002 10:22:48 AM 
> 
> the flow rate for the filter is usually specified by the filter maker... if you have the original packing, its probably stated on the box somewhere... if not, you can try searching their webby for the info.
> ----------------


Allen,

I am using Eheim Liberty 100, it has a maximum flow rate of 100gph and it is meant for tanks up to 20g. But as the flow rate is also adjustable, I have set it to the slowest/minimum...

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## DEA

DOC is dissolved organic carbon
you normally don't do this test
just pointed it out as an indication that N isn't everything
if you can't do water changes daily, just do them as often as you can

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## Irn-Bru

got a thermometer from Petmart today...
my tank temperature is 24-25C... is this a good temperature?

this is after moving the lights to be about 7inches away... but my plants are not exactly bubbling now...  :Sad: 

also, my cherry shrimps seem to be more adventurous now, coming into the open... and they are redder than before...  :Smile:

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## PeterGwee

Irn-Bru..I don't see why you should move your lights away even further when it shows that your temperature is 24-25 degrees which is ideal for keeping plants..The only problem I think is when the air-con is &amp;quot;off&amp;quot;...which is when the temperature will rise to 30-33 if the room is stuffy and not much ventilation (in an air-con room..should be huh?). What you need to do is to balance the amount of light, CO2 and nutrients in order for the plants to photosynthesis.

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## Irn-Bru

hi peter,

my lights were moved higher a couple of days ago... that could be why the temperature is 24C today...

its hard for me to monitor temperature after office hours as i seldom (almost never) do OT...  :Smile: 

but my lights are off at 5pm and the air-con is offed at about 7pm... maybe it could be the weekends???!! air-con is off and my lights are ON... hmmmnn...

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## PeterGwee

Kekekeke..why don't you bring the tank back? Might be easier to maintain and look after mah.

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## Irn-Bru

then who will motivate me to come to office?  :Smile: 

wonder if other office tanks have similiar problems...

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## Allen_1971

Ah but you are supposed to go to work because you love your job... or am I spouting nonsense... ok maybe I'm spouting nonsense... heck, its too early in the morning to be coherent... maybe after lunch when I really wake up I'll say something sensible... for now I need to work *groan*

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## Irn-Bru

then maybe i should apply for a position with NA...

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