I used to be indecisive........now I'm not sure anymore.....
I have turned around and (hopefully) FINALLY decided to go for liner in one piece. The reason for that is because I've found a source that sell at factory price, butyl 0.75mm liner with 35 years guarantee. I am willing to pay their price which is 3 times cheaper than the one found in any shop. Another reason for going for one piece liner is because I'm kinda fed up with black liner and the company I found sells liner in black, green, sky blue and sandstone. Which gives me another dilema....sandstone or skyblue???????????. I am still waiting for the samples so (maybe) when I get them may be easier to take my decision.
Skyblue brings the best color in fish(most of shows use blue liner for koi display) and I am very tempted BUT may look ugly like hell if the whole garden in context. Sandstone may blend better with the rest of the garden.....anyway.....i will see.
Regarding your question Sue, I was going to take out the old liner altogether anyway. Mainly because I am gonna increase the depth of the pond (now at an average of 2.5ft and i want to go an average of 5ft). Actually that was my intention in the first place but my gf stopped me at that time. Four months later, 5 more books red and £800 spent on 4 fishes she has decided to sacrifice half of the garden in favour of fish. So back to the drawing board ( I meant to the shovel!!!!). From 500 gallon pond to 5000 gallons pond is a big jump. Also a big jump (read NOSEDIVE) in our bank account as the whole filtration system needs changed and the new one is gonna cost about £1800. Anyway I have pics of the garden the way it was 5 months ago, the way is now and as soon as i'm done I will make a website with all the steps taken.
To all the people who decided to reply to my thread a big thank you.