UV isn't something I'd thought of but now you put it on the table I can see it being useful.    The bacterial count idea is (yet another) theory... but I'm mentally assembling some tools to test it...  e.g.  http://appslabs.com.au/bacteria.htm

A low EC/TDS and a low pH (6) should be enough to keep bacterial counts low. I've considered a UV in the past but I think it would be unnecessary overkill and may add some extra heat to the tank water. 

Can I ask if you kept track of nitrates? Did they stray much past zero?

No I didn't test anything other than pH and EC.  Which reminds me to write them down.  Today pH=6.5, EC=54µS/cm

This time around they are in a 50l tank with approx 1 drop per second fresh rainwater dripping in

= 4.3l fresh water/day

= 8% water change per day

= 45% water change per week

according to http://www.angelfish.net/DripSystemcalc.php

 

I have not measured nutrients in the rainwater but I'd be surprised if not close to zero (I maintain the gutters, have first flush systems etc).. but I will check just for completeness.

I previously lost my zebs to what I think was a red cyanobacteria outbreak that I let go unchecked.  For completeness of this thread I'll repost from a response I made in Fishmosy's thread.

Quote

I had the zebs in a 40l plumbed with a constant drip in (2 drip per second?) and screened overflow. No sudden water changes.

The water supply is a blend of Melbourne tap and rainwater (mostly rainwater, maybe 20% tap).  EC ~ 40-50 µS/cm.  The tank started clean with a nice "hint" of green biofilm, but over time developed a very thick brown algal mat that coated most surfaces including plant leaves.  I have 8 tanks on the same constant drip and only one other tank has developed the same brown biofilm - it thickly coats the glass consistent with how blue-green looks (at it might very well be) - because it was brown as it developed I thought it might have been just a good natural film for the zebs  - brown diatoms are common with new tanks and usually burn out, but in this case they didnt they just got thicker until manually removed.  My gut feeling is that this was actually a chance colonisation by a brown cyanobacteria that exploited the low nitrogen rainwater in the tank (all theory and no substance - I've loaned my microscope to someone so can't look at the "algal mat" further.. yet..).

In retrospect perhaps the drip wasnt a good idea (less control) or maybe my water quality -  even with rainwater - isn't good enough (I would have said unlikely previously)... or perhaps just a chance colonisation by something bad.

Even from day one however I still had that concern of them not showing enthusiasm for the food choices I was giving them so I'm stoked to see yours and Jamie's recent posts with some shrimp gluttony.

I can confirm this now. since losing the zebs the tank has sat idle and the biofilm in the tank went very red and manky and obviously red cyanobacteria (likely toxic to the shrimp). Loads of small bristle worms moving around in the slime.

So I've dosed with Chemiclean and will re-set the tank for some other purpose.

I have also noticed clearer glass on several tanks since switching to pure rainwater over the last two months  (no mixing with tap).  The mixing with tap is too inconsistent.  When the flow rate is very low, the rainwater pump doesn't kick in so its possible my header tank fills mostly with tap, then when I'm doing water changes and using more water the pump fills it mostly with rainwater. Far too inconsistent.  For my next run at the zebs (which may be very soon) I'll make sure I use rainwater only.

An opportunity arose and I couldn't say no...

 

 

This new tank has only been set up for a couple of weeks prior to getting shrimp, but all the contents (rocks, plants, moss) have come from mature tanks rich in biofilm.  Only the glass is clean and thin inert sand layer is fresh.   Same size as before ~50 litres.  The day before the shrimp arrived I swapped the sponge filter for a mature filter from another tank.  Not maturing the tank properly for a month or more is a risk but whatareyagunnado.  I did consider removing all the shrimp from another mature tank but then discovered there were Paratya larvae in the water I wanted to keep.  So new tank with old contents it had to be.  Since the sand is clean - I'm temporarily adding some grotty potted plants in slimy plastic pots from other tanks to supply more biofilm and the shrimp are quickly finding them and cleaning them (small amazon sword bottom pic).

The water this time around is pure rainwater from 100KL storage (so water params should be relatively stable) with a constant drip in and out (about 3 litres of 50 litres replaced each day) = ~30% water change per week.  KH <1,  GH<1, pH ~6.0 22C.  I drip acclimatised the shrimp to the rainwater over a 2 day period with no losses.  Colours are bright and I'm optimistic.

I followed @fishmosy's lead and bought some Boss aquaria shrimp snow to try as a supplemental feed and a test of a just a few flakes brought more interest from the shrimp than I've seen from the zebs before for other foods.

 

 

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Edited August 30, 20169 yr by Grubs
linkage

Woot Woot.... good luck Grubs. ill be watching with interest as I'm also attempting to keep them.

 

Good luck mate. Your shrimp look really healthy too. The clear body sections are transparent and the whites and blacks are crisp. 

I'll be following and cheering along as always:-)

Would love to hear an update on your progress with these zebs,

I've started keeping them recently too.

Re: them not taking food easily-I have found they go nuts for live frogbit- tear it apart like crazy, and also frozen aqua one brand blood worms, but they haven't touched much else I've tried to feed them.

cheers

18 hours ago, Zebra said:

Would love to hear an update on your progress with these zebs,

I've started keeping them recently too.

Re: them not taking food easily-I have found they go nuts for live frogbit- tear it apart like crazy, and also frozen aqua one brand blood worms, but they haven't touched much else I've tried to feed them.

cheers

Careful how and what you feed. If your TDS increases too much, the zebs will get stressed and die off.