Setting up my second loach tank.

[MultipleTankSyndrome]

Time to discuss one of the less glamorous parts of this tank. For obvious reasons, no pictures of this.

I'm absolutely shocked at how much poop the roselines and black kuhlis are putting out. They're lightly fed and not supposed to be high bioload fish anyway, yet the filter and prefilter couldn't disagree more!
The part I'm most shocked about is that the black kuhlis are putting out a ton of long strings of poop, almost pleco-like. Never have I ever seen or heard of this from kuhlis. ?

What does this amount to? When rinsing the filter sponges and prefilter, I got enough to fill an entire 9 liter bucket (and a bit more! Probably 9.5 liters total!).
All that from just 9 less than half-grown roselines and 24 black kuhlis of varying age, which are but a small amount of size and number of all the fish this tank will have and when all those fish grow up.
I would be surprised if I don't end up with at least 40-50 liters of poop water per tank cleaning at that point! Blech

There are 2 upsides to this, though.
The houseplants and lawn absolutely adore all that poop water. And seeing it in the bucket reminds me of how much I have removed from the tank, which is quite satisfying.

 

[Midwater]

Is it merely poop? Or is it time to treat with Levamisole?

 

[MultipleTankSyndrome]

It's poop alright. Well brown all over, not 'stringy' in the internal parasite sense at all even though it is in the pleco sense.

Edit: Also, parasite poop would not be nearly as 'gunky' on the filter as normal poop. Another thing that makes me think this is just fine.

 

[Midwater]

It is a while since I had khulis, but I never noticed a poop problem. I have got an awful lot of loaches of various types, being many thousands or tens of thousands - the volume of a few knulis. I have also got some roselines. Never noticed a poop problem.

Only thing that makes a poopy mess (in another tank) is a six inch L137.

What sort of diet are they on?

(And if they are relatively new, I would treat with Levamisole anyway.)

 

[MultipleTankSyndrome]

They're well established. Levamisole is illegal where I am, but I do have flubendazole.
I'm feeding them Tropical Krill Gran.

On second thought, after this conversation, the poop doesn't seem that bad. It's only 1/6 the length of the loaches, but perhaps it being more than I expected gave the illusion that it was a lot.
Also, the sheer number of kuhlis (24) may be a contributor. Plus, with the prefilter, poop that goes through to the actual filter is going to be much finer and color the water more at rinsings than if there was no prefilter (in which case, more poop would stay solid and not color the water, even though the amount doesn't change).

 

[cockroach]

200th comment on this thread, woo!

cockroach , something you might want to know about surface agitation. I have noticed the roseline sharks breathe faster and even occasionally try to gulp air at the top within a short time if the pumps are not agitating the surface.
I realize you said your fish were fine with just water movement and no agitation, but just something you might want to know since it was brought up and I noticed it. The difference in our cases is almost certainly related to the fact that your clown/yoyo loaches are not as oxygen sensitive as roselines (which seem to come from streams that generally have very high agitation).
And it makes a lot of sense too. Surface agitation both increases the surface area of water to dissolve oxygen, and mixes oxygen it dissolves deeper into the water, so it's easy to see why this makes an appreciable difference for roselines or similar fish.

Hopefully this helps for future reference.

When I say there was no surface agitation, I mean no real breaking the surface and creating choppy water or bubbles. What I did have however, was a huge volume of water coming in contact with the surface via circulation pumps moving water from below a false bottom to the surface and down again. This added a large amount of oxygen to the water. The fish before, which had high oxygen needs, and the fish now, all have the same amount of oxygen in the water.
But in most cases, yes, I have found surface agitation to work best especially in conjunction with water movement. Why sponge filters are a proven winner for decades.

 

[Kieraivingston]

 

[MultipleTankSyndrome]

When I say there was no surface agitation, I mean no real breaking the surface and creating choppy water or bubbles. What I did have however, was a huge volume of water coming in contact with the surface via circulation pumps moving water from below a false bottom to the surface and down again. This added a large amount of oxygen to the water. The fish before, which had high oxygen needs, and the fish now, all have the same amount of oxygen in the water.
But in most cases, yes, I have found surface agitation to work best especially in conjunction with water movement. Why sponge filters are a proven winner for decades.

I see! Thank you for that elabotation, it's actually pretty enlightening.

 

[MultipleTankSyndrome]

I think I'm going to be putting a dark background on this tank to help the roseline sharks color up more. I'm not big on black backgrounds (hence why I scraped the black paint off that the previous owner had), but what other color to choose isn't so clear.

One of my thoughts was this shade of greenish-brown. Looks natural and it seems to be coloring the roseline sharks in the image well, only problem is that it or a similar shade may be hard to get as a color on printed paper.


Another thought was somewhat dark blue, like this picture of full grown roselines for sale at the pet store. It colors them up just as good as the first (note that my camera did not capture the brightness of their green, it is about the same as the first).


Any other color suggestions welcome!

 

[Midwater]

Blue seems to bring out the colours, but personally I do not like it at all. Far from natural. Some LFS use blue for that reason.

Black might be more similar to the murky depths. I am a little indifferent.

I do not put backgrounds on tanks. Tanks are made of glass on all four sides, so let natural light shine in from all four. Even if one side is against the wall, then pull it away a little.