Water Testing

[N0body Of The Goat]

I've regularly testing the water in my Rio240 recently, along with daily minimum 10% water changes and excess Seachem Prime, after moving my 8 teenage adult Ilyodon xantusi through to this tank in the last couple of weeks. As always, I was extracting pippettes of water from just below the water surface, never getting anything higher than 0.25mg/l.

Well this lunchtime, my female Steatocranus tinanti was doing some serious flicking on the sand, so I decided to get a sample of water from near the tank floor where she was flicking instead of the usual wter surface sample... Imagine my horror when I get my first ever "grass green" 2mg/l reading! (Emptied tank to bottom ~3cm and refilled gradually with excess Prime)

This makes me wonder if I have been sampling incorrectly since I started the hobby, I got a borderline yellowy/lime green 0-0.25mg/l reading yesterday before a ~25% water change on this tank...

Where does everyone else get their water samples from?
Are we supposed to be getting samples from near the tank floor?

 

[ZoddyZod]

very interesting.

Could the area you took the 'floor' sample from be in a flow dead spot with maybe a build up of detrius very nearby?

 

[N0body Of The Goat]

Thing is, this tank has loads of current (Juwel integrated with upgraded 1000lph pumpset; Eheim 2078; Koralia 1 powerhead), giving ~3500lph turnover. The mass of bogwood is placed long ways, just off the back wall, allowing the current to whip around it unrestricted to the front, where I took this sample from (there is a video clip taken just after the ~95% water change this afternoon in the video section).

 

[Tizer]

I tend to sink the tube in a fair distance, but primarily that's to avoid any oil/food from being sucked in from the surface. But that said, i cant actually remember the last time i tested my main tank.

 

[ZoddyZod]

hmmmm, since it's so well circulated I find it odd that any section of the water could have higher concentrations of ammonia.

 

[Akasha72]

I've always taken from the top using a syringe - I thought this was the right way to do it. It begs the question - it's that why fish normally go to the surface when there's ammonia in the tank?

 

[JDs4me]

Dare a newbie to the forum suggest that it is very unlikely that you will get even current flow around any kind of obstruction big or small, fast flow or slow! There will be little eddy currents in there, regions where back-flow can occur, possibly forming a pool of uncirculated water...basing this on my oceanography studies of a few years ago, and my white-water kayaking! But no reason why in a microsystem you shouldn't experience the same behaviour, especially if current flow rate is constant and always from one direction. I wonder if making slight alterations to the direction of inflow would be possible as that would alter flow-direction throughout the tank?

I am presently doing a fishless cycle, and take samples from different regions and water levels in the tank each time in order to identify any 'dead zones'...hope you don't mind my input! Hope its of use...

 

[Tizer]

I cant imagine a 240l tank with a 3500lph turn over having a single dead spot myself. i've got a 4400lph powerhead in my 5 foot tank and not a single area is still Could it be that the tubes were not cleaned well enough and there could be some residual "xxx" in there causing false readings? I tend to put mine in boiling water before i test.

 

[N0body Of The Goat]

Well things get more intresting, I've just finished a ~95% water change on the 48x12x15 (which runs an APS2000EF, so ~1200lph turnover in a 140l tank), after getting a 0.5mg/l ammonia reading from a sample near the tank floor, yet this tank always has perfect yellow from the water surface. This tank gets daily 25-50% water changes, because of the ~29 Ilyodon xantusi youngsters in there and the consequent increased feeding regime. Might explain why my Microsynodontis sp.1, who spend a lot of time on the tank floor, had pink/red undersides to their gill area, yet the upper water Ilydon looked fine.

JDs4me, very true about the mini eddies that form, definitely one of the downsides of having high flow that goes around the tank rather than a true river manifold system (I'd love to try and build at least one of these for uniform one direction flow, as I have a lot of high current riverine fish).

Tizer, my test tube cleaning does not sound as good as yours, I simply leave the tubes and the lids in a sink of hot tap water for ~15 minutes before rinsing (done in one batch lot once all 8 or so tubes have been used through the week).

The other factor why I think I've had these spikes on two tanks is to do with food, I've recently started using Hikari Carnivore pellets on a lot of my tanks, even the youngsters go bonkers for them when I crush them to a powder. Their high protein levels could have produced a massive nitrogen input boost that the bacterial colonies are still trying to catch up with.

 

[Tizer]

Any change in your tap water ammonia over the holiday period? Doesn't really explain differing readings, but might be the cause of abnormally higher ones? i know a lot of water companies "shut down" over holiday periods and processing isnt always as perfect as it could be etc.

 

[Aqua Tom]

I always use a pippete to get my sample & always from the very top layer of water.


Tom

 

[OldMan47]

I don't like to have a surface only sample so I hold the tube a few inches below the surface and let it fill. Then I dump out the excess down to the sample volume line. I have never tried sampling down near the substrate so I have no idea what my samples might look like down there. When I have any indication of trouble I do a massive water change, not a small 20% to 30% one. When I am dealing with troubles I draw the level down to about 1 or 2 cm and refill with dechlorinated water. The actual level is determined by the fish in the tank. At 1 cm, most of my livebearers can get enough water to keep them covered so that is the minimum level for them.