Soil questions need answers please

hi i am a newbie enjoying learning about soil composition for houseplants. i have read the sticky post...thanks tapla....but have a question or two need answers if you can help:

if i use bark will i need to add lime to adjust the pH, is there an ideal pH, and what is the best method for measuring it?

in some recipes grit is used. for what circumstances or plants is grit useful?

if i use a mix that is low in water-retention then i will need to water more often. if i go on holiday for a fortnight in the summer this could be a problem, is there any way around this?

should i wait till early summer to re-pot and root manage a plant? is it worth potting on and removing as much of the old compost and replacing it with the new mix now?

over here in england we have plenty of rain-water, lucky us! if i use only rainwater then will i have no salt build-up problems, is rainwater pure enough?

hope these questions make sense and thank you in advance for any help you can give me...

I'm going to touch on some of your answers, and leave a link that should help you immensely if you want to learn about soils. It will answer a lot of questions, both asked & unasked. Then, if you have more questions, ask here or on the other thread as you wish.

if i use bark will i need to add lime to adjust the pH, Usually but not always is there an ideal pH, and what is the best method for measuring it? There is an ideal pH for containerized plants that varies by plant and will be about 1 full number lower than the same plant grown in mineral soils, but as a hobby grower you'll probably drive yourself crazzy trying to maintain anything close to an 'ideal pH'. Concentrate on getting close and making sure you have all the essential nutrients available for uptake.

in some recipes grit is used. for what circumstances or plants is grit useful? It's use isn't specific to particular plants or types of plants. How it's used varies, but it's primarily used in the soils I use to adjust water retention and ensure good aeration, the later being a function of its size - so size is important to it's ability to fill a need.

if i use a mix that is low in water-retention then i will need to water more often. Yes if i go on holiday for a fortnight in the summer this could be a problem, is there any way around this? Friends, family, automatic watering devices, tenting ....... It's a trade-off, but you get a years worth of better potential for your plants in exchange for the inconvenience.

should i wait till early summer to re-pot and root manage a plant? Yes, unless it's an emergency is it worth potting on and removing as much of the old compost and replacing it with the new mix now? I do all my houseplant repotting in the summer so I can work with their energy flow instead of it working against me, so I'd only repot out of season if forced to. Pot up anytime

over here in england we have plenty of rain-water, lucky us! if i use only rainwater then will i have no salt build-up problems, is rainwater pure enough? Yes

The link: http://davesgarden.com/community/forums/t/1073399/

Al

thank you as ever for your help...

..... and you for the opportunity TOO help.

Al