how to raise soil pH?

So i bought a large bag of B&Q Multi-Purpose Compost for seeds, cutting and young plants. The very first time I got it, the mix was smooth and consistent. So this time when I got the bag I thought it would be the same as last time, from the first glance the texture looked the same.
So I repotted my plant into the mix and didn't thing much of it. When I check the run off I almost had a heart attack. This crap was at pH 4.0!!!!! and I water had a pH of ~8.0. So that plant is pretty much dead now so I don't care much for it.
My question is, how can I raise the pH of this soil dramatically without adding any extra soil to it as my budget is quite tight this holiday period and I don't have the facilities to mix loads of soil? Can I add some bicarbonate of soda to it or keep the soil soaking in high pH water for a while? Some ideas as of how I could fix this thing before I plant new seeds. Or should I toss this garbage and look for new soil?

Thanks

Edit: I've read pretty much all the posts about raising pH when the soil is in use. This acid soil is not in use, yet.

I pretty much answered the question myself. I'm gonna try to add eggshells to this crappy mix to try and stabilize the pH. I have access to pretty much unlimited amount of eggshells as I work as a cook in a coffee house I'll post update when I get to it.

ph up or dolomite lime with work

Dolomitic lime takes a long time to break down, calcified limestone or liquid lime you mix
with water would work a lot better.

I use pellet lime to raise and buffer my ph when growing in soil.

I use ashes to bring my ph up.

So I got a load of eggshells. I'm gonna bake them in the over for about 30 mins and then crush them as finely as I possibly can. Then I'll mix about a cup of eggshell with about a gallon of soil, water is and let it sit for a day or 2. Anyone has any ideas if that will help stabilize my soil?

EvilMuffin said:

So I got a load of eggshells. I'm gonna bake them in the over for about 30 mins and then crush them as finely as I possibly can. Then I'll mix about a cup of eggshell with about a gallon of soil, water is and let it sit for a day or 2. Anyone has any ideas if that will help stabilize my soil?

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I'm not sure but I think the calcium will reduce the amount of acids in the soil even further and lower the ph. Domolite lime is to bring the ph down, I use refined ashes to bring the ph up.

bird mcbride, you got it all backwards here. The lower the pH the more acidic the soil is, the higher the pH the more alkaline. So therefore i want to raise the pH and get rid of the acids.

bird mcbride said:

I use ashes to bring my ph up.

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Here is one of the best, cheapest, and fastest ways to raise your Ph. Add 2 to 3 tablespoons per gallon container, when adding during the grow, mix with water and water into the soil. You should see results within 24 hrs.
Hope this helps

Do I need to use ash from a certain burnt material or would tobacco and/or MJ ash work too? P.S. My tap water is approx 8.0 pH so I could theoretically just flush the soil a couple of times to get it within range, right?

hardwood ash is the best, it has the most N and trace elements. Do not use any wood which has been treated for waterproofing or such as this will put heavy metals and poisons into the soil. If you have a yard just picking up sticks and such will help or from a fireplace. Flushing will help but will not hold the Ph in the soil, the woodash will be much more long lasting solution.

bird mcbride said:

I'm not sure but I think the calcium will reduce the amount of acids in the soil even further and lower the ph. Domolite lime is to bring the ph down, I use refined ashes to bring the ph up.

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Lime brings the PH up by reducing acidity......