Downsizing Tanks And Fish

It is always difficult to know what is best in this kind of situation. The tank you have now is the minimum recommended for silver dollars; without knowing the species of rainbow I can't say what their minimum size tank should be.
As you are aware, both of them should ideally be in a shoal, though I quite understand you not wanting to get more of them. That is the tricky thingsabout the last survivors of a shoal.

One thing you could consider is advertising them on the website aquarist classifieds, stating how old they are. Someone who already has a shoal might be willing to take them in, especially if you offer them free.

If you do decide you want to continue keeping fish, you may well be happier finding a new home for your current fish and get another, smaller tank. Something around 60 litres would allow a nice largish shoal of small tetras or rasboras etc, and a shoal of one of the dwarf cories. That would keep a 60 litre tank slightly understocked and easier to maintain. And your 200 litre tank could also go on aquarist classifieds if you don't want to keep it.

But before you decide on any course of action, plan ahead. If you do decide to rehome your current fish and get a smaller tank, keep the filter or at least the media inside it so that you then don't have to cycle the new tank - or at least a cycle would be much shorter if you can't fit all the old media into a smaller filter.

Hi there,

That's good advice thanks and more than anything - it made me think - do I really want to re-home them - I've had them such a long time and looking at them... any pet is a pet I committed to and so is a pet for its life -  thank you for reminding me of that even though you didn't directly.
So the conclusion is that I have their welfare in mind more than anything - re-homing means I don't know if they will be okay so - keeping the size of the tank... to make them happy; and me can you help to get my enthusiasm back with a community they'll be okay with?
What should I start to introduce - another dollar or two to start with? any special size? He/ she is glum since the other one died - the rainbows (eastern rainbows I was told) are their usual selves so they are less of a worry than a lonely dollar - what else would balance them up - I know they are all plant eaters and have had a few diff species before - plecs do well with them and angels but I don't want to overstock with biggies again though, hence them dwindling in the past - natural progression as they grow I have allowed them more space by not restocking but 3 is a bit sad!
All ideas welcome and I'll have a go with the community tool.
Thanks again and a good lesson for starters - think what you will do many years later!
Kirsty

Great brilliant help - thanks very very much - tank size is fine re dimensions so I'm okay and am in the process of finding silver dollar friends - there are loads selling them on the web and some close to me in the NW so will be able to get some larger ones too.  The bottom dwellers have done well in the past so thanks again - I did need rescuing!!! Kirstyx