Help choosing tank mates

[Byron]

The swordtails are these guys "Xiphophorus hellerii", as I understand there captive breed ones which is where the specified colour/styles come in.
Seriously fish list them as max 8cms max?

As an adult, Swordtails range from four to as large as six inches; in aquaria 4-5 inches is normal, with females slightly larger than males. You will commonly find them from two to three inches in pet shops. At that size they are generally six to nine months old.

I know the site owner of SF, SF does say a 120 cm tank length is minimum, and that is big if the fish only max at 8 cm so I suspect the fish length is a slip.

Finding wild caught swordtails is very difficult unless you deal with an importer or exporter. The decades of crossing Xiphophorus hellerii with X. maculatus (the platy) has produced the many colour varieties.

Does them being captive breed make a difference?
I've seen lots of messages with people keep species well outside they listed parameters and that multi generation captive breed species are quite different to their natural counter parts (this is anecdotal obvs)

I did comment on this in my previous post. Some species adapt more than others, captive breeding is not going to change this unless the species is able to evolve further which is likely the case. But some do, some don't. Being "different" from the wild species is relative, the species is the species and it has evolved to a very specific set of circumstances. Fish are not "domesticated" in any manner, they are still wild creatures regardless of captive breeding. At least up to now.

I cant even find a site that's lists all the hardness parameters for a species so how do you know them

Seriously Fish lists GH for species. Fishbase provides GH data for most I think.

 

[Andrew waterson]

Very useful heads up on the swordtails, I did wonder why it was suggesting a 1.2m tank for an 8cm fish!

Would you be able suggest a few options for a community tank of this size and water parameters?

On the cycling I was planning on adding plants after the cycle was complete then fish (1/2 stocked or less initially) straight after.
Is that the correct approach?

 

[Byron]

Very useful heads up on the swordtails, I did wonder why it was suggesting a 1.2m tank for an 8cm fish!

Would you be able suggest a few options for a community tank of this size and water parameters?

On the cycling I was planning on adding plants after the cycle was complete then fish (1/2 stocked or less initially) straight after.
Is that the correct approach?

As I explain in the post I linked previously, if you intend live plants you are better not to "cycle" with ammonia. Set up the tank, plant it, and get the plants growing. Fast-growing plants, and floating plants are best for this, will allow you to begin adding fish. Ammonia and nitrite will be zero, provided the plants are growing, and you don't add too many fish. I have done this in a day, but I know what I'm doing and to spare you any glitches, I recommend going a bit slower.

As for fish options, we first need to know what rainbow fish species and how many mollies you are intending. Depending upon the species of rainbowfish, there may not be any available space when the shoal is introduced. Shoaling fish (rainbows are shoaling species) need a group, minimum number depending upon species intended. SF has data on all this. Mollies are largish fish, males 3 inches, females 5-6 inches, though you are best with just males to avoid fry explosions.

 

[Andrew waterson]

I'm not sure any rainbows will actually work with my water unless I do a single species tank (which I really want to avoid, I think I'd just go for cold water in this case)

Melanotaenia boesemani is good for the water, but at temp of over 26 seems to rule out any other hard/alkaline water fish who all seem to be 24 to 26

Melanotaenia boesemani was my preference, but is right at the top of the hardness level and outside the pH level

I haven't come across any other rainbows that would work, so I think there out as well

Which means I'm down a very expensive bacteria community tank!!

Anyone have experience with similar water had how you got past it?
I would have thought hard and alkaline is relatively common in big cities!

 

[Byron]

I think it was agreed (Colin posted, no one is objecting) that most any of the rainbowfish will be OK as far as you GH and pH. You need a good sized group. Melanotaenia praecox? Colin knows this group better than I do.

I am not expert in cold water species, but I doubt there are many suited to this tank. ??

Livebearers only...mollies, platy, guppy...could be very colourful. Black mollies, red/black/blue platies.

 

[Andrew waterson]

And I was planning on 6 Mollie's (1 male 5 female)
They do seem like might work, although they seem to need even hard water (hard water than London is impressive!!! But guessing it's a different aspect of hardness) so may be out as well

 

[Andrew waterson]

Good news on the dwarf neon rainbows, they we're one of my preferences
Would be looking at at least 6

 

[Byron]

Earlier in this thread the GH values were given as 268 ppm which is 15 dGH. This is fine for mollies (and any livebearers). However, I would caution you on male and female; five females will have a batch of fry every month, and they cannot all get eaten. Males only will avoid this. With GH so long as you are within the species range, you are OK, and there is usually some latitude. Temperature is a different thing.

The M. praecox I would suggest more, 8-9. The larger the shoal the better as the fish will be more interactive and colourful. With this group, you could have three male mollies? The black would be a nice contrast to the colourful rainbows. Or perhaps there is another rainbow species that would combine with the dwarf neons.

 

[seangee]

I too have problems with hard water in SE England. The usual recommendation is to choose fish based on your water for good reason. However it is possible to change your water - but it does require commitment.

The easiest way is to mix your tap water with RO water which is essentially water with everything stripped out of it. So a 50/50 mix would halve your hardness. It would also halve the nitrates in your tap water by diluting them. In my area Maidenhead Aquatics sells RO water at £4 for 25 litres. So if your water change is 75 litres per week and you choose 50/50 you would need to use 37.5 liters every week - and you would need to have spare water in case of emergency water changes etc. That's where the commitment comes in. This will most probably lower your pH but the actual amount is difficult to predict. As others have pointed out hardness is the important factor.

 

[Andrew waterson]

Thanks everyone this has been incredibly useful.

I do plan on working with the water as is, the rebalancing act seems very challenging and I've been warned against it as a novice (water fluctuations being quite harmful).

I'm going to go back to the drawing board and do so more research while the tanks preparing.
I'll be back with a list MK2 in a few days/weeks

But I think I can see a viable community tank from this info

Hi seangee,

Did you stick with the water as is or go for the RO option?

 

[Colin_T]

Melanotaenia boesemani will be fine in your water. My concern with them is that full grown males can be bullies and might pick on the mollies. If you keep even numbers of male rainbowfish (eg: 2, 4 or 6 males) that are the same size, then they display to each other and usually ignore other fish in the tank. However, if you only have 1 male or 3 males, then they display to anything in the tank, and that includes barbs, livebearers, and anything that swims If this happens, the big male boesemani might get too enthusiastic and knock the male livebearers around. The rainbows are unlikely to kill the livebearers but they can dominate and stress them.

If you have 2 male boesemani that are the same size, they will spend all day chasing each other and showing off to each other (and to the girls) and ignore the other species of fish in the tank. This behaviour is normal for all rainbowfish regardless of species. So if you get rainbows, try to have even numbers of males and try to get them all the same size. Smaller rainbows are less of an issue due to their smaller size.

Male Glossolepis incisus (New Guinea red rainbow) are considered the most aggressive rainbowfish and big males will bully other male fish in the tank especially if they are smaller than the G. incisus. Again tho if you have 2 males that are the same size, there is fewer issues.

-----------------------
If you want colour, then 8 Melanotaenia praecox, 5-6 black mollies, 5-6 gold or red wagtail platies or 5-6 pineapple or red wagtail swordtails. With this combination you could even breed the rainbowfish in the tank and sell off surplus fish. The rainbows spawn in clumps of plants (Java Moss is readily used) and you move the plants into a hatching tank where you rear up the fry.

 

[seangee]

Hi seangee,

Did you stick with the water as is or go for the RO option?

I stuck with the water for many years. In my community tank I do have captive bred tetras and corys. These have always appeared healthy but nothing has ever spawned in the tank, and I have long suspected that mine don't live as long as they could. At the beginning of the year I started filtering for nitrates because my tap water has 50ppm. Since I am already filtering my water I added a softening filter to the mix a couple of months ago. Similar process to RO (but without the waste and quicker if you diy) and using 50/50 my tank has stabilised at 10-12 dGH (was 16).

My Tetras appear to be noticeably brighter. This could of course be wishfull thinking but I do have several obviously gravid tetras and sids (dwarf chain loach). Never seen this before and encouraged by these results I am going to switch to 75/25 this weekend. I went gradually because I didn't want to shock the fish who have been living in hard water for many years and also wanted to make sure I wouldn't trigger a pH crash. My pH has dropped from 7.8 to 7.2 and KH from 20 dKH to 16 so I suspect that is unlikely.

 

[Sarah73]

Hi All,

I'm just about to embark on my 1st tropical fish tank setup
Will be starting a fishless cycle in the next few days, so hopefully adding fish in the next 6 weeks or so

I'm planning on a community tank, I have a 160 litre tank, sticking within the 1cm per litre an fish max size of 15cm.
It will be moderately planted

My water is hard alkaline (London!) with the following stats from the tap (from testing and backed up by my post code water report)
PH: 7.6-7.8
Ammonia: 0
Nitrite: 0
Nitrate: 30ppm
Hardness: CaCO3 268ppm, Degrees Clarke 19, Degrees German 15

The below is my current list and predominately based on water requirements and internet research!
6 mollies (small variety like neon orange)
6 swordtails
4 rainbow fish (smaller variety probably Bosemani)
1 Blue Gourami
1 Indonesian Flying Fox

This should be under 160cm with them all at full\max size (I know the live breeders may impact this in the future!)

The all are listed as liking PH up to 8 and have 26 degrees C as an ideal temp

Would they make good tank mates
From my reading the main ones sticking out at the mollies and Gourami, its sounds like the sometimes bully each other

Mollies are kinda like swordtails, but swords are longer. You need at least 6 rainbow fish. You are way overstocked with 12 mollies/swordtails.