While this is a high quality method of watering for expensive or sensitive crops and plants, this is way overkill for guava. I just throw down whatever slow release fertilizer I have on hand all over the plant and water in.
Guava is not PH sensitive like other plants.
You're spending a lot of time and money doing what you're doing, and could skip it.
Also, warning on the hose filter, they are so effective sometimes that they remove too much calcium and your plants will suffer because of it. This is especially evident with tomatoes.