Stocking suggestions please :) started cycling today and have done seine water tests. Ph is coming out at between 7.8 and 8, water is very hard in my area (as per my previous posts) nitrate from tap is near enough bang on 5. Hoping to get a gh/kh test done by LFS tomorrow if need be.

Also any suggestions on which of my current fish need to be rehomed or would be better suited in the bigger tank.

Oh and tank is 120x30x40 approx if this helps, with external filter and a larger sized gravel substrate.

All my readings come from tap water stood for 24 hours.

Good idea to get the gH tested but you will find it very hard as you suspect. On that basis you may want to reconsider:

2x kissing gourami - max ph 8, max hardness 19 dH, but softer is preferable and they will grow too big for the tank.

6x neon tetras - pH under 7, hardness under 7 dH

3x oto catfish - pH under 7.5, hardness under 12 dH, but softer and more acidic is better, prefer sand substrate.

1x red tailed black shark - pH under 7.5, hardness under 15dH (softer is better). Can become increasingly aggressive and territorial with age.

That leaves you with the Three Spot Gourami and the Danios. The problem then is that the Danios are temperate fish who like cooler ate - ubder 24C which is too cool for the Gourami and limits you as to other choices.

The other way to approach it would be to soften the water and reduce th epH by mixing in some RO water. You could then keep the Neons (and preferably increase their number), Gourami and RTBS, but would be best off rehoming the Danios.

I'd still recommend rehoming the Otos as the substrate and tankmates don't suit them and the Kissing Gourami as they will become too big and can be quite aggressive. In case you're unaware, the "kissing" they do isn't affection, it's aggressive lip-locking as a show of dominance and potentially a prelude to fighting.

Yes I noticed one of the kissing Gouramis is very hostile towards the other, it's almost twice the size now. Won't let the other eat.

I don't think I'm up to the challenge of RO water. So I'd prefer to buy for the water I have if possible :(. Would cichilids be an option? Or is the tank not big enough for the quantity needed to thrive?)

Also... What is the difference between gh and kh... I can't for the life of me figure it out :(

With your water Rift Lake Cichlids are an option - Tanganyikan or Malawi, but you'd need to rehome all existing fish in either of those cases.

gH - general hardness is what we mean when talking about how hard or soft water is. That can't be altered other than by dilution with pure water.

kH - carbonate hardness, or alkalinity also known as temporary hardness refers to the proportion of dissolved carbonates in the water. These can also dissolve into water from calciferous rocks and gravels. If kH is very low, pH tends to be acidic and to be unstable.

Higher levels of kH buffer the water against pH swings - water tends to have a higher pH and to resist anything that would change it.

kH reduces in tanks over time as the biological filtration process involves carbonates being used up by the bacteria as they process ammonia into nitrite and nitrate. That's one of the reasons for regular water changes - to replenish carbonates and prevent a filter crash. When kH is depleted, the bacteria can't do their job, water becomes acidic and ammonia/nitrite accumulate.

Something tells me finding suitable fish is going to be fun.. Maybe I should just have an army of shrimp. Or lobster maybe, grow my own dinner ;).

Thanks noodle I'll check the care sheets and see what I can find that I like the look of and will post back for some critism :)

Have a good look around and try looking for Tanganyikan and Malawi fish as the water you have sounds pretty much ideal. There can be some complications as to which species are compatible, and you can't really mix firsh from the different lakes, but a set up with fish from one or the other can be a real pleasure.

I personally like Tanganyikans and will be setting up a tank for them as soon as I have some spare cash

I've got to say though... I'm not a massive fan of cichlids, personally i think they are ugly fish, though I'm sure I can be proved wrong ;)

tanganyikans are far from ugly, in general, but the tank would be too small for a malawi community though

I habe to disagree there. There are thousands of cichlid species, and some I don't find attractive, by many are beautiful. How can you call any of these guys ugly? All SA soft water species, but all cichlids

I'm not a cichlid fan either, angels are nice but that's about it. Then again looks are not everything!!!