Fish Dying, Need Help - Water Stats

[norbie]

Hello,

I really need help, my fish keep on dieing here are my first ever test results, and copy pasted template.

Tank size: 36x12x12 = 22.44 U.S. gallons, which is approximately 87.3 liters.
pH: 6.6
ammonia: 0
Nitrate - 200 NO3 (mg/l)
Nitrite - 0 NO2 (mg/l)
kH: 0
gH: 6
tank temp: 25C / 78F

Fish Symptoms (include full description including lesion, color, location, fish behavior):

- Several fish died in the last couple of weeks - no visible signs or reason for deaths. Some fish are sitting on the bottom of the tank for periods then swim off fine again.

Volume and Frequency of water changes:

- Weekly 30%

Chemical Additives or Media in your tank:

- Recently been putting in General Tonic medicine to try to combat the problem.

Tank inhabitants:

- Now only 2 swords, 10 guppies, 5 platies, 2 scissortails, 1 silver dollar, 1 honey gourami, 4 other small fish that i cant remember, 12" common pleco.

Recent additions to your tank (living or decoration):

- Possibly those 4 other small fish were added a few months ago, cant see that as the problem - probably water issues TBH.

Exposure to chemicals:

- N/A

Digital photo (include if possible):

- N/A

Please help!
I'm guessing those test results are the issue - why has that happened and what can I do about it?
I water change with bottled spring water from the shop (my tap water is high in nitrate), and don't use dechlorinator as I didn't think it was necessary if I don't use tap water.

Before you shout at me saying I'm overstocked I have a new 125L tank that they will be moved too soon - I have the pleco because he was 'rescued' from a 20L tank, and he loves my tank.

 

[kimmers318]

I am certainly no pro...but even when I did a fishless cycle I never had nitrates that high. My card reads up to 160 ppm, not sure what the NO3 is. I am using Aquarium Pharmaceuticals test kit. With that many fish and that high of nitrates you are probably guessing correctly that that is the problem. My only advice would be try daily small water changes to keep the nitrates in check until the bigger tank is ready....and hurry on the bigger tank!

 

[norbie]

Thanks, kimmers318

I'm doing a 50% water change now, with bottled water - nitrate in that is 6 mg/l - should sort it out! I also have bought something that reduces nitrate in a tank.

 

[norbie]

I just did the water change, and it seems to have made a big difference - the water test now indicates that the nitrate level is between 50-100 mg/l nitrate.

The stuff I put in is Tetra NitrateMinus - This is meant to lower nitrate over time.
http/www.tetra-fish.co.uk/tetratropical/...p?productID=194

I would still appreciate people's comments though if possible - are all my other figures OK?
Is there anything else I can do?

 

[triskele]

Hi Norbie,

Could you check and let us know what's the lowest pH your pH test kit will measure. The reason I'm asking is that your KH (essentially buffering capacity) is 0. If that KH value is correct then your tank will be prone to large pH variations.

Also if you have the time and enough spare tests, could you test your tap water for all the parameters and post them as well.

Triskele.

 

[norbie]

Hi,

I tested my tap water earlier but I've thrown away the tests now.

I will post new test results for the tank, and for the tap water tomorrow for you to look at

My testing kit is the Tetratest 5 in 1 test strips.
The lowest the pH goes is 6.4
I said mine was 6.6 as it was in between the 6.4 and the 6.8 colours.

 

[OohFeeshy]

Ah, well, that particular test kit is pretty awful IME. But nitrate reading is awful, if your tap water is like that, you should contact the water company (as that level is bad to drink), and perhaps use RO water (which has 0 nitrate).

 

[norbie]

What's RO water?

I've contacted them before and made them come and take a sample to test - they said the nitrate level was well within their standards.

But high nitrate may be fine for us, but not necessarily for fish.

 

[Nospherith]

Your tank is overstocked. A 12" pleco in a 20g is ridiculous, and cruel. You have so much fish waste that's going through the nitrate cycle that it creates up to 10x the amount of nitrates that there should be. That's why your fish are dying. It's not your tap water.

RO stands for Reverse Osmosis. It removes electrolytes from the aquarium to generate comparatively pure H2O.

 

[norbie]

I don't consider it cruel especially when he's had such a big upgrade from a 1 foot tank, and is having another one soon.

By the way I got my calculations wrong - he is about 6" long (half the width of the tank which is 12"!

 

[norbie]

New test results:

Tap Water:

Nitrate - 25 NO3 (mg/l)
Nitrite - 0 NO2 (mg/l)
10 GH
3 KH
7.2 pH

New Tank Results:

Nitrate - 90 NO3 (mg/l)
Nitrite - 0 NO2 (mg/l)
6 GH
3 KH
6.6 pH

 

[phlawed]

I don't consider it cruel especially when he's had such a big upgrade from a 1 foot tank, and is having another one soon.

By the way I got my calculations wrong - he is about 6" long (half the width of the tank which is 12"!

not bashing you, but 12" and 6" is a BIG BIG difference when dealing with plecs. Plecs are high waste producers in exchange for thier services. But, either way, you levels have dropped by over half, which is a good sign, but at the same still bad, anything over 40 nitrates is usually the standard of concern. You need to get below 60 to be on the safer side. Anything more is a high risk to your fish in the tank.

 

[triskele]

Norbie,

Those water results are looking a lot better. Your tap water is not that bad (not ideal with the nitrates but nor disasterous either). My concern with the KH was that quite a bit of your stock are livebearers and they seem to do better at neutral pH and middling water hardness levels (though a live bearer expert will be better informed than I on their exact tolerances).

RO stands for reverse osmosis. I think that some fish shops sell the RO water, or you can buy an RO unit which fixes up under your sink. It basically pushes water through some fine filter membranes removing the larger molecules (heavy metals, nitrate etc). Again, it would be worth doing some reading up on that if you are interested. One option, if you are unhappy with using your tap water alone would be to use a mixture of RO water and tap water for your water changes.

Something like that, combined with regular water changes will keep your KH above 0 and prevent a PH crash (which your fish certainly won't like). You water parameters (once the nitrate is a bit lower) seem ideal for some of the dwarf cichlids, apistogrammas etc.

All the best,

Triskele

 

[norbie]

Thanks for your replies.

Is my tap water ok to use for water changes then do you think? (with dechlorinator of course)

I have been using bottled water for a while, but it restricts me when i want to do a water change as i have to drive down to a supermarket and stock up on water!

How can I reduce the amount of nitrates I have left in there then? More water changes? Would it be ok to do that now? How much would you reccomend (If i can use tap water I can do it straight away)

 

[triskele]

Hi Norbie,

This is just my opinion (others may disagree <grins>) but I think that your tap water is okay to use (with dechlorinator as you said). A fifty percent water change with the readings you have given would lower your tanks nitate level to (90+25)/2 = 57.5 mg/l NO3.


A second fifty percent water change in 2 days time (lets say arbitrarily your nitrates in the meantime had risen to 65 mg/l NO3) would result in a nitrate concentration of (65+25)/2 = 45 mg/l NO3.

I would carry on doing this type of water change until you get a nitrate reading in your tank of below 40 mg/l NO3.

I would then leave your tank for a week and then re-measure the nitrate. This will give you an idea of high much your nitrate rises per week.

E.g. Starting nitrate level of 35 mg/l, a week later NO3 level of 65 mg/l.

To return your tank to a nitrate level of 35 mg/l you would need to perform a water change of;

(65+25)/? = 35
90/? = 35
90 = 35 x ?
Therefore ? = 90/35 = 2.57

To convert that to a percentage (in water change volume) = 1 part tank water (of 65 ml/l NO3) plus 2.57 parts treated tapwater (25 mg/l NO3) = (2.57/(1+2.57)) x 100 = about 70%

In this example scenario a 70% water change weekly is a bit drastic, and I would probably perform 2 water changes a week of 50% (which would be equal in this example to the one drastic weekly water change of 70%).

Apologies if the above if a bit confusing, I'm not sure I've explained it that well. If there's anything in there you think I've got wrong or is a tad confusing let me know and I'll try to explain with the aid of caffiene so my brain is functioning better <grins>

All the best,

Triskele