Not So Great Kitty Litter

[JustKia]

I had plain old play sand in my 33Gal and my plants did alright - not spectacular, but then I wasn't dosing ferts or CO2 and only had basic lighting but they looked OK and grew pretty well.
When I moved everything to the 72Gal I used 100% clay kitty litter and capped with play sand.
At first it seemed OK - but now the litter is turning black and stinks to high heaven and seems to have killed off my plants

the sand hasn't turned black and isn't black where it meets the edges of the tank - it's the actual litter that's gone nasty.
I had maybe 35/40% of the substrate planted and 1000s of malaysian trumpet snails. Fish/snails/shrimps are all looking OK.
Water stats are all stable ammonia 0; nitrite 0; nitrates 0-20 (there are nitrates present in the tap water too); pH about 7, it's a 7 from the tap and I get a 7 after a water change but over the week it can drop to 6.8/6.6 (hard water with very little buffering capacity). I don't have tests for trace elements, so can't comment. But, the only thing that's different is increased flow and the substrate. I don't see that increased flow is going to be the problem.

The only thing I have noticed is my filter gunging up rather frequently, which I'm also thinking is down to the kitty litter. I've been doing 50% weekly water changes on this set up from the beginning and sometimes an extra change because the water looks "dusty" (kitty litter?).

I'm in the process of removing the substrate completely and I'm going to replace it with just play sand again. As I've got a pair of bn plecs it seems pointless to have a layered substrate.
You live and learn. I can't say it's a substrate I would recommend.

 

[betta fish]

Oh dear! I have clay litter in my 65 litre mixed with play sand and planted, I've noticed the plants grow alot more in the clay than just sand although there is alot of dust about perhaps I just need to vac it more, either way I think it looks good although if it ends up going black and smelly like yours I won't be best pleased! how long did it take before it went like that? just so I know when to expect it and was it a gradual process or sudden? how deep did you have it? mine is about 50/50 clay/sand and about an inch thick.

 

[JustKia]

27 Sep it went in, so just over a month.
min 1" litter/1" sand upto a max of 1.5" litter/2" sand.
I'd say it's happened pretty quick given it's only been in there a month.

I've got 1.5" sand in my fry and divided male betta tanks with no blackening. 3" sand in my sorority tank - no blackening. Had about 2" sand in the 33Gal and no blackening problems - although this tank is currently empty (awaiting delivery of new inhabitants), except for a few shrimp and some snails it's still fine.

 

[Mr Bliss]

Thanks for the warning. I've been under the impression that this is mostly an issue in soil-based substrates where there's plenty of organic material, but now that I read about it, apparently some of the smelly H2S-producing bacteria can use inorganic carbon (CO2/bicarbonate) as a food source too.

I think cat litter compacts into very dense clay when submerged, so it's probably best to mix it with sand and/or peat fiber, or use as a very thin layer, to avoid these extremely anoxic conditions.

 

[bae1994]

does the whole tank smell then??

or do you do gravel vacs then as your not meant to when using clay and sand

 

[JustKia]

Mr. Bliss the litter doesn't compact into a dense clay. I used "non clumping" litter which is actually baked, so although absorbent it doesn't go "clayey" like raw clay.

Bae1994 the tank itself doesn't smell bad, more like garden soil after a spring shower, but as soon as any substrate is moved it stinks - worse than rotten eggs.
I don't gravel vac the sand - never have in any of my tanks. I've got enough flow to make sure nothing gets a chance to just collect on the substrate and of course the MTS and corys are always rootling the surface too.

To explain some more...
I put sand at the front edge of the tank for asthetic purposes, then the kitty litter on the tank base and capped off with sand.
Started planting up, although my "scape" wasn't finalised as I already planned on getting more plants. My male bn plec decided he didn't like my scape anyway and quickly created 2 large holes, 1 either side near the back. Because of the flow the substrate has shifted slightly and is slightly deeper on the right side of the tank than the left.
I'd noticed that my wisteria wasn't growing as well as it always has so far and I had a fair bit of elodia that's been growing well but had stopped and lost it's "green-ness" for want of a better term.
I figured I'd move the wisteria to an area of less flow and give the elodia a pruning - get rid of the older bits and replant the tops. As soon as it (gently) uprooted the wisteria the most foul smell came up too. I carefully moved the sand aside (not wanting to disturb loads of substrate) and the litter is all blackened. Checked in other areas of the tank - same thing, sand is fine, litter is black and smelly.
The sand at the front of the tank, where the light hits it, hasn't turned black.

OK, so I don't have a hi-tech set up, don't have any expensive plants and my tanks will never look as awesome as some of the planted tanks on here. But I'm also not the grim reaper of the plant world either. But those plants did just fine in the smaller tank - similar stock, same filter, same water stats and source, about same wpg.

 

[ellena]

How bizarre! What brand of cat litter was it? I've got some cheap-as-chips p@h clay stuff in one of mine, been in there well over a month and not seen any bad side effects. The main problme with it is I'm terrified of disturbing it and bringing the clay to the top

 

[Nick16]

cant beat using akadama, a far safer bet. i wont go near cat litter.
make sure you get the right stuff though.

 

[JustKia]

It was p@h own brand 100% clay, non clumping (ie baked so it won't go mushy) kitty litter.
Still damage is done, and now it's a case of damage limitation.
Moving out a whole substrate when you've got a stocked tank and only a small emergency tank isn't an easy task.

 

[Nick16]

yeah, i had that with my 120L fully stocked plus a few extra fish from my 240L. i had to put them all in a 40L litre from about 30-45 mins. i had it well oxygenated and in the dark. worked though!
yeah, in terms of baked clay with a high absorbsion rate, akadama is the way to go. (if you get the right stuff, otherwise it may go the same way as cat litter)