Hi. Have a couple of very nice discus that I was just looking after. they are smallish still and in a 2foot bare tank with several other fish. However I wish to move them to a bigger tank (150L) which is gravelled and planted with mainly java and amazon sword and some plastic plant. Also has some wood which has been in other tanks for some time. However the small tank has a ph of 6 and the new tank (filled 2 weeks ago and has no fish yet) has a ph of 7.2 to 7.6.

although I can take the water from the 2 foot tank with them the ph will be much higher still than they are used to. Suggestions please as to best way to handle the shift to ensure the discus don't get too stressed? Though I would keep some gba's with them.

From what ive read the best thing is to keep discus in bare bottomed tanks to keep things clean and ensure they aren't stunted at all? Also they do better in larger groups unless you have a pair 2 don't usually get on all that well.

Regarding the ph as long as you aclimitized them and had the big tank fully cycled (or moved filters as well) they should be alright.

I put a single guppy into a newly cycled tank to test to see whether it's habitable...how big are your Discus?

I put 5 4cm Discus into my 6footer and now they're all around 6cm mark and it's only been 2months..leaving them in a small tank would stunt their growth

Yes have put some guppies and swords in now. the intention was for these discuss to spend at most a week in the two foot tank but circumstances (that are not of my making) have dictated somewhat different and now the owner has decided they don't want them back so hence the need to rehouse. Understood that discuss were very susceptible to PH fluctuations and there is a massive difference between the two tanks so will start with water changes in the two foot to bring it up gradually to around 7 anyway and thought to put some peat in the filter to reduce the ph in the newer much larger tank. what is an ideal range for discus and if it is a lower p then will the peat be sufficent to keep it down.

Maybe you could add driftwood or peat to lower the pH? If you did lots of water changes on the 2ft to raise the pH at the same time to make the pH change less great, it would probably be better for them.

read somewhere a while ago that Discus would adapt faster to lower pHs than higher pHs (compared to which pH they lived in)

just drop down ph to 6 to 6.5...

if there are no other fish in the new bigger tank lower the pH a bit yes you can use peat i find that the best way or for more longterm driftwood can work but peat is a surefire way to do it quickly. or transfer water from old tank to new tank. luckily for you it is much better to go from low pH to high pH... if it's the other way around the acid can burn and stress the fish = death. after they've adjusted don't mess with the pH just keep it as steady as possible and yes barebottom is ideal and 50% water changes daily.. tho they can be fine with 25% per week but the more the better.

oh yeah just as a last point in the wild they're in 4-5 pH possibly lower so naturally they like it more acidic as most south american fish do.

hope this helps

thanks for all the suggestions. Was a bit concerned about these fish and although I love them have never tried keeping them as always thought they were too difficult. However have had them in my care sincec July anyway so must have been doing something right so far. They are in their new tank and appear to be very alert and eating. Just trying to sort out some tank mates thought maybe a GBa or two.