PPS Dosing, anyone use?

[krisw]

I've been reading through some old threads on APC, and came across PPS, or Perpetual Preservation System. I guess I'm at least a year behind on this, but the main premise is to keep the nutrients in your tank balanced, avoiding the need for weekly water changes. Being lazy, and somewhat conservation minded, the constant water changes of EI and even SeaChem's recommended dosing have always bothered me. That said, I was wondering if anyone in GWAPA has tried PPS, and found the claims to work out?

For a ton of very well-documented material on PPS, start here:
http://www.aquaticplantcentral.com/foru ... ables.html

[fredyk]

I have not been able to take the time to figure out PPS .

My plants always seem to perk up after a partial water change.

Mark

[Jeff120]

I thought about it and have read a bit about it, I personally dont mind doing water changes weekly, I dont really dose EI either, I dont think they high amount are really needed. I dose Ei basically divided by 2, With that I can go 2-3 weeks and all is fine. PPS seems like to much work.

[krisw]

I dose Ei basically divided by 2, With that I can go 2-3 weeks and all is fine. PPS seems like to much work.

You know, when I was reading PPS, I was actually thinking of you Jeff. I wonder how far off your dosing is from what they're doing. In particular, the charts you've shown me where you meticulously dosed and tested for a few weeks, and then setup the auto-doser seems to be very much in-line with what PPS does. Hopefully, after that initial period, you wouldn't have to do much testing.

[SCMurphy]

PPS is supposed to tell you what your tank needs, you have to keep testing if you trim or change plants because the needs change. IE is a way to keep a hypereutrophic nutrient level. Both work if you are diligent in keeping with the program. I think PPS would work better in a non CO2, low light, low tech situation.

I don't change water a lot. I don't dose the water column much at all, a little K or Fe here and there. I'm not keeping stem plants either so I can get away with that.

[DelawareJim]

I agree with Sean. I've been contemplating trying PPS for a while and doing the weekly tests at first as they recommend and then stretching things out to testing every couple of weeks, which PPS is supposed to let you do. But then I thought, like Sean, I don't have any stems in my main tank so why make more work for myself?

Generally though, I prefer PPS to EI simply because I hate wasting stuff, and the idea of intentionally over-fertilizing and then dumping half of it down the drain each week rubs me the wrong way.

Cheers.
Jim

[Jeff120]

I think the PPS is more of of a continual dosing, like Sean said when anything changes, plant mass, water change, clean filters, anything you have to start all over. EI IMO is the best guide to using ferts. Adjust accordingly to your tanks needs. My main goal is to not run out of anything, you dont need to dose your tank to precisely 12ppm KNO3, 1 ppm PO4, ect, you just need to keep it from bottoming out or you will have problems, algae, and over health of plants. Some plants dont like low levels of nitrate.

[DelawareJim]

Jeff;

I don't think you're starting over, I think you're adjusting what to add each testing period based on the factors you mentioned.

As plants grow, you trim, clean filtes, etc. the plant uptake changes. The spreadsheet tracks what you added from the last set of water tests, what the plants have used based on this weeks test, and then calculates what you should add based on water volume, plant mass and other changes to bring the comcentrations up to the optimal level you established.

I will admit it is a more complex way of reaching the same end.

Cheers.
Jim

[krisw]

I was wondering how it takes into account the changes of plant mass. I imagine that if you maintain the a relatively consistent aquascape, and maintain a consistent trimming schedule, that the dosing schedule would become predictable enough to provide exactly what you need.

As another difference, PPS also seems to focus far more on balancing Mg and Ca than the traditional EI dosing scheme seems to. Somewhat related, Edward on APC (creater of PPS) has a post arguing that if your GH is stable, that you can safely inject CO2 with 0 dKH without worry of a PH crash killing the fish. I believe the focus of Mg/Ca in PPS is attributed to his experiences in this regard. (This is interesting to me because I'd like to get my apisto tanks down to < 6.0 ph while still being a heavily planted tank.)

http://www.aquaticplantcentral.com/foru ... crash.html

[DelawareJim]

I think the changes in plant mass are taken into account by calculating the difference between last tests concentrations minus this tests concentrations. It assumes the entire difference is attributed to plant uptake.

So, for arguments sake, if your NO3 test last Saturday said 8ppm and the spreadsheet calculated you needed to add X concentration to bring your total NO3 concentration up to 12ppm, and this Saturdays NO3 test shows you have 8ppm again, then you know that the plants used all X of the NO3 you added last week. As the plants grow the test this week may show 7ppm meaning you used X+1 (all you added last week plus what ever concentration your solution uses to give you the 1ppm more the plants used).

When you trim, they will use less, maybe X-1.

In theory, you are only adding what the plants are using as they use it.

Cheers.
Jim