The rent increase is most likely valid.

How much did my rent go up?

Rent cannot be increased more than:
5% + your CPI (Consumer Price Index, which is 3% for Oakland) = 8% or
10%, whichever of these is lower.

If the increase is Illegal:
You can write a letter addressed to the landlord informing them that the rent increase attempt is illegal. You have the right to continue paying your current rent (before this new increase). There’s always a chance that your landlord will try and continue to pursue that invalid rent increase. So if you do receive a 3-day notice based on the increased amount, be ready to pay the increased amount. You can petition to get that money back through the Rent Adjustment Program.

If the Landlord insists that you pay the rent increase, and you believe it is illegal you can complete a Rent Adjustment Program Petition within 60 days of receiving the rent increase notice.

If the rent increase is illegal and you have repairs issues, this is the perfect time to cite those. A good way to enforce your rights to a habitable unit is to ask for repairs. When responding to a rent increase, you can include repair issues.
To address this, you can write a letter about the invalid eviction notice that includes a list of repair issues that need to be fixed and a desired timeline of when you would like those repairs completed by.

If the increase is valid.
Paying the amount stated is recommended. If you cannot pay, you can try to negotiate with your landlord in writing but note that they can say no. Remember that the notice has to at least be a 30 day written notice.