Ferts = Ammonia?

[tam]

I'm hoping someone can help me work out what's going on with some tank readings/shrimp issues.

I got five cherry shrimp last saturday - lost two within 24 hours and another yesterday (not sure about the status of the other two), so I got them the shop to test a water sample and they said my Nitrate was 0 but ammonia was showing the first reading (can't remember the number).

The tanks well established, planted, low stock and it seems pretty unlikely I should have ammonia at all - could the ferts give a false positive? I use Tropica Specialised 2-3ml per week 75l tank, but in fairness I also do small water changes (about 10-15% every two weeks).

On the other hand the shrimps TDS was 974 when I checked the bag, so it could have been I didn't acclimatise them slow enough - but would that explain the lastest death a week on...

 

[PARAGUAY]

Have you done anything what could have unbalanced your filter there should be some nitrate reading

 

[Andy Thurston]

On the other hand the shrimps TDS was 974 when I checked the bag, so it could have been I didn't acclimatise them slow enough - but would that explain the lastest death a week on...

thats quite high even for cherry shrimp so it could be the acclimatisation but one of the shrimp suppliers i use said that shrimp cope with tds lowering much better than a sudden increase in tds (imagine heavy rainfall diluting the natural waters)
just out of interest what is the tds in their tank
I dont test my water for anything other than tds, ph, and temperature but do tropica ferts contain ammonia (urea) as the nitrogen source

 

[tam]

Nope, nothing I can think of that could have unbalanced the filter. I rinse the top fleece/sponge layer in old tank water when I do a water change but otherwise haven't disturbed it.

My tank TDS is 215, ph is 7.8, and temp 24.5oC. Water is remineralised RO so no nitrate or anything else from tap.

With the RO and low fish stock I know my nitrate tends to be lowish which I why I use the tropica specialised, but zero?

 

[Andy Thurston]

just found this
http://www.fishforums.net/index.php?/topic/247927-diy-fertilizerpmdd/
I have read somewhere else that tropica specialised uses urea/ammonia an its N source too but cant find it
so perhaps ammonia could be the problem but I still wouldn't trust the shop test results
are you adding kh when you remineralise your ro water? I struggle keeping cherry shrimp because my tap water is low in calcium but I haven't lost so many shrimp that quickly (maybe 1-2 per month)

 

[tim]

If the Tds was 974 from the lfs it could just be deaths from shrimp already weakend from not so great conditions, IMO the lfs will generally point to ammonia in your tank so they don't have to replace the livestock, a drop of 700 odd Tds could likely finish off already poorly kept shrimp, personally I would worry about finding a new supply for cherry shrimp, your tank sounds fine, if you want to catch the lfs out take in some tap or ro water and see if the test results come back the same. The trace amount of urea in tropicas ferts would not harm livestock IMO, big company with rigorous testing procedures before anything is released for sale.

 

[tam]

I was worried about the kh so I swapped to tropic re-min a couple of months ago which includes it, but maybe I haven't changed enough water to bring it up. I might do a couple of slightly bigger changes to make sure I've cycled most of the water.

They've offered to replace them but didn't give me any on the day because of the ammonia reading. I guess I can skip ferts this week and see if that resolves it.