Still Have Concerns

[Kaidonni]

After rehoming the Clown Loach on Friday, I'm left with five White Cloud Mountain Minnows in what is meant to be between 45-50 litres. It'll probably be at around the 45 litre mark in the end, and I'll probably have to add further water in when I remove the castle that the Clown Loach hid in (don't want to be too hasty since there will be beneficial bacteria all over it, I don't want to cause any issues for my tank's biological cycle - perhaps about Wednesday is the right timing, before the bacterial colonies resize too much?). However, everything I read on the internet suggests that 50 litres is the minimum for White Cloud Mountain Minnows, so I'm thinking my tank is still too small for the remaining fish. I'm not going to be upgrading to any larger tank - I have no plans of doing so - so my choices are either to keep the Minnows in what I think is too small a tank (even if it's only by a matter of litres, it's still too small), or rehome them. If I rehome, I'm probably not getting any other fish, so that'll be it for me and fish-keeping for the moment. Keeping them in with the Clown Loach probably stunted them, and continuing to keep them will probably still stunt them and cause problems.
 
I'll be keeping an eye on their gills and looking out for any problems. I've already fed some pea to deal with what I suspect is constipation (long trail of poo on at least one Minnow). I don't generally blanch peas, I just thaw them out, de-shell one and cut it into very tiny pieces and feed a bit at a time - must they be blanched?
 
As to the castle... I conducted a Nutrafin nitrite test Friday night and last night, it's still detecting minute amounts; less than before the Clown Loach was rehomed, and this is also comparing it against a test tube of untested (and also tested) tap water, otherwise, it'd probably look virtually clear...but still reading it. I'm under the impression there should not even be the faintest of differences between untested water and tested water (or it means nitrite). Perhaps I haven't left it long enough, or perhaps my filter isn't strong enough to move the water around the tank effectively and that's causing issues?
 
I also have to figure out my lighting, because I've never used the light itself due to the Clown Loach - now he's gone, I'm concerned about it being too bright. Plants at the top are only a partial solution. Is daylight sufficient? The guy who has rehomed my Clown Loach did remark on some of the plants browning because there wasn't enough light in the living room. The only light I really use is a lamp in the corner of the room when it gets dark outside, it isn't particularly bright and doesn't cast too much on the tank - is that sufficient during the darker hours? It is turned off at night (once that goes off, the whole room is in darkness).

 

[Akasha72]

Hiya,
 
you have to do what you need to do. If your gut is telling you that the tank is too small for the minnows then go with your gut. But give up fish keeping? Why would you want to do that? There are loads of small fish on the market that will love a 50 litre tank as their home.
 
There's a plethora of fish to research - have a look at rasbora's - you can even get micro rasbora's that are so small a large shoal of up to 20 would be lovely in a small tank. There's tetra's too that stay small, if you've got sand substrate take a look at panda's cories or pygmi cories - again both are small and stay small. 
 
Don't give up, that would be such a shame

 

[Kaidonni]

The sites over the internet all say different things...10 gallons (US or UK I don't know, but it puts it in the range of 38-45.5 litres), 45 litres, 50 litres, 57 litres, 60 litres...
 
I don't ever listen to my gut. I don't make big decisions based on emotions or feelings because if I did, I wouldn't have rehomed the Clown Loach due to the terror of killing him through the rehoming.

 

[BiggTexx]

What are the dimensions of the tank?

 

[Kaidonni]

~58cmx26cmx27cm in terms of where the water fills, although I'm not measuring exactly from the very edges but where I think the inside of one side meets the inside of another. I am also topping up further today and will need to take additional measurements for that.

 

[BiggTexx]

Can you measure the true size?
 
You either have a US 10gal or US 15gal.
 
For instance, a common US 15gal is 24" x 12" x 12" (roughly 61cm x 30cm x 30cm)

 

[Kaidonni]

60cmx29.5cmx29cm (lengthxwidthxheight up to where the lid starts - not lifting the lid off until later, a few cms more to add to height).

 

[BiggTexx]

OK, so that will be a US 15Gal and roughly 55 Litres.  Substrate, decor and a few plants would probably put you around US 12.5-13gal (not sure of the litres).
 
I would say the White Clouds are fine...

 

[Kaidonni]

What about removing the castle, though? How late is too late? The bacterial colonies will resize to the Minnows, and I have to take into account that extremely faint nitrite reading I mentioned. Would it be best to leave the castle a few more days, or is that pushing it?

 

[BiggTexx]

If you have other decorations, substrate and an established filter, then removing the castle shouldn't hurt anything at all.

 

[Kaidonni]

The filter (which I cleaned yesterday and changed the filter floss), gravel, heater and an airstone (apart from the plants).

 

[BiggTexx]

You mean you just rinsed the filter media, right?

 

[Kaidonni]

Yes. I remove water from the tank and wash the filter media and the filter housing in the dirty water...and proceed to accidentally knock filter media back into that water multiple times while trying to properly place the new floss (balancing the inside of the housing that holds the pads on the side of the bucket...).

 

[TwoTankAmin]

One of the things most folks do not know about the nitrifying bacteria/archaea is that is it photosensitive. It is not fond of light. This is why filters are tinted or solid colors. Yes the bacteria will colonize hard surfaces of all types but there are a few caveats to that statement.
 
1. The will colonize out of the the light. That means the undersides of things not exposed to light or the insides of them, but
2. The bacteria will colonize expand and grow in numbers where the most hospitable places are. This means where there is circulation. The bacteria are fixed in place so everything they need must come to them.
3, In a filter of the right size with proper media, this will be the best place in any tank for the bacteria to colonize. This does not necessarily mean all the bacteria is there or that even most of it. It means more is likely to be there than any place else.
 
So, as to your castle. There is no bacteria living on the outside where it is exposed to direct light. If there is any appreciable amount inside, it is because the water will circulate though it as well as it will other places. There is likely little or no bacteria on the underside of it due to circulation being poor there. I learned all about this when researching the archaea vs the bacteria in terms of ammonia oxidation. If you are interested you can read here: Differential photoinhibition of bacterial and archaeal ammonia oxidation
http/onlinelibrary.wiley.com/doi/10.1111/j.1574-6968.2011.02457.x/full
 
In your case, where you have no ammonia reading and a barely readable nitrite level, you should have 0 nitrite pretty soon if not already as I write this. Bear in mind that reproduction of bacteria appears to accelerate as it nears the end. I say appears because the rate of doubling doesn't change. What actually does change is how much more bacteria is needed to get 0 readings. If you have only 10% of the bacteria built up than is needed and it doubles, you are sill 80% short of the total needed. But if you have 80% of the needed bacteria, it must only increase by 25% to hit full capacity which means it should take about 25% as much time to reach that level as it would to double.
 
But the best part of having to deal with nitrite when there are fish present is that a small amount of salt in the water (actually the chloride in the salt) can be used to block the nitrite. No water change is needed until its time to remove the salt from the water. In many cases normal weekly water changes will do this. (See Some Facts About Nitrite http/www.fishforums.net/index.php?/topic/433778-rescuing-a-fish-in-cycle-gone-wild-part-il/)
 
 
 
 
 
 

 

[Kaidonni]

Well, I removed the castle and will wait to see what happens. Maybe some small rocks might be suitable (with dark spots where bacteria can hide) as a replacement.
 
I'm hesitant to use salt for this nitrite reading...it's even less than in my other thread. Without the tap comparison, it'd likely be impossible to even see the slight colouration. It's that slight. This is under the kitchen light - in ambient daylight without any other sources, the higher readings I used to get were quite difficult to see even with a tap comparison by the side. I'm hesitant to use salt fullstop for Minnows. One grain would probably do the trick, but might also be over-kill.