pH trending down

[WarDaddy]

I have a 50 gallon, with a sump.

40 lbs of ecocomplete, 50 lbs of color quarts
35 lbs of slate rock

Lighting currently is 6 hours 48 watts of t-5 10000K, 2 hours 175 MH 6500K. I plan on making the lighting 4 hours each as soon as I get the co2 and pH stable, and the plants start filling in.

Current Parameters GH-5 KH-9 pH-5.85

I have pressurized CO2 going through a home made reactor (phos ban reactor filled with PVC pieces, flow in at the top and out through the bottom). I am pushing about 90 BPM. Drop Checker is a blue green color, so I would like more CO2. CO2 is on 60 min before lights and off 30 before they turn off.

The tank is 4 weeks old, has been planted for 2 weeks.

My first recorded pH was 7.4 day after day I see a drop in pH, measured first thing in the morning, after the lights have been off all night. the reading this morning was 5.82. This is via pH probe on my AC3. I have good surface flow, drop checker is not showing full green yet, and still the pH drops and stays down.

Is this something to worry about? Should I be doing something about the pH? I am doing weekly water changes from the tap. Water is run through a water softener (nothing I can do about that) and carbon filter.

Thanks,
Bryan

 

[Philosophos]

Your pH seems pretty low for your KH, and your KH exceeds your GH which is a bit atypical. Are you on some sort of sodium ion exchange resin? What are you filling your drop checker with?

-Philosophos

 

[WarDaddy]

yes the water softener is a sodium kind.

I have the dh4 (or kh4) solution in the dropchecker as provided with it from AGL.

When I started the GH 3 was KH was 5 I have been adding Barrs GH booster 1/2 tsp on each water change, and I added some baking soda to bring KH up.

 

[Philosophos]

While the pH is a little low, many plants will still be fine. It's the sodium that bothers me in this case.

Is every part of your house rigged up to this resin? Could you install a bypass or use the garden hose?

Just out of curiosity, what's your dosing regimine look like?

-Philosophos

 

[WarDaddy]

I have one hose bib that is not filtered (maybe), I may be able to run from it, although that would not be fun, and the extra work would likely reduce my likelihood to do water changes. I will have to test all my water outlets to verify. I am in FL the water is REAL HARD with out the filter.

here is what I am doing...

M/W/F - 2.5ml KNO3, 0.5ml kH2PO4
T/Th/Sa - 1/4 tsp k2so4, 10ml CSM+B, 2ml Iron
Sun - 50% water change 1/2 tsp Gh Booster

I have made liquids from dry fertz like this:

CMS+B - 2 cups water with 2 TBS dry
KH2PO4 - 500ml water with 3 TSP dry
KNO3 - 500ml water with 2 TBS bry
Iron - 2 cups of water with 35 grams iron

 

[WarDaddy]

The probe is reading 5.45 right now...so I pulled the pH probe out and put it in a glass of water, for giggles...
So far the read out is not changing 5.45 ...
looks like my probe is bad. however, from what I am reading, pH is not something that I need to really worry about. I will go buy a test kit and randomly check it for fun, but I am thinking I have a probe problem, not a pH problem.

 

[ordloh]

Yeah I'd say your probe is bad, it's not really possible to have a kH of 9 and a pH of 5.45. Anything other then carbonic acid would lower the kH, and you'd require a ton of CO2 to drop the pH that low with a kH of 9.

 

[Tug]

Wasup

Arrr, low nitrates (say 1/PMDD dose), good light and CO2. For the sake of argument say the water column is 182L (forgo any in the sump for now). It has O2/CO2 and light. Maybe even warm t5 lights, w/175MH blowing in for 2 hrs - I like the big bang theory. Hit, (aim at) a taller dose; 10 - 20ppm NO3 - 75% nitrate uptake. As soon as that light goes on that's not nearly as bad, as say having less.

 

[Philosophos]

Do you have a water quality report? It'd help to know what you're doing next, and it would help me to make sense of your dosing.

Here's what I'm seeing right now for dosing:

N 1.793854586
P 0.219832231
K 18.91219098
Fe 6.955893235
Ca 0.57248681
Mg 0.285000945

Based on this (still in sloppy form) math formatted for spreadsheet:

Nitrogen:
=((62.00501/101.10332*5200*6)/500*2.5*3)/160

Phosphoros:
=((94.9714822/136.0856722*5600*3)/500*.5*3)/160


Potassium:
=(((39.09831/101.10332*5200*6)/500*2.5*3)/160)+(((39.09831/136.0856722*5600*3)/500*.5*3)/160)+((78.19662/174.25984*(1/4*6400*3))/160)+((78.19662/174.25984)*(16.8/31.2*5.6/2)/160)*1000

Iron:
=(((35000/100*10)/473*2*3)/160)+((((4300*6*10)/473)/100*6.53*10*3)/160)

Calcium:
=((40.0784/202.15522)*(9.3/31.2*3.1/2))/160)1000

Magnesium:
=((24.30506/222.17039)*(5.1/31.2*5.1/2))/160*1000

I'll check all my numbers over again after you provide the water report, but as it stands now things look a little under dosed and a little overly complex.

-Philosophos

 

[WarDaddy]

you mean a water report from the water company, I can... but like we established, my water is filtered.

here is a link to the report for my county...
http://portal.pascocountyfl.net/por...7/2008+West+Pasco+Annual+Water+Quality+Report

 

[Philosophos]

Yes, I figured the filtration would mess with everything. I'm concerned about sodium levels with the filtered stuf. The report is also useful because if the filtration only takes out part of the nutrients, I have at least a maximum level to look for.

As it stands, I'd recomend increasing N and P by about 10x the amount they're at now. This means you'll probably be able to skip out on about 3/4 of your K2SO4 dosing, since plenty will come along with the KH2PO4 and mainly the KNO3.

Your iron looks pretty high; up around what I've seen luxury uptake max out at in a couple of studies. Probably about 5-10x what I dose. I'd love to see what kind of plants that makes for once you've got everything stablized.

Anyhow, once the NPK is nailed down we can start worrying about sodium, pH and CO2.

It's best to start from a known stable method, and from there eliminate outside issues, and then after that start tinkering with things.

-Philosophos

 

[WarDaddy]

so I f I am reading that correct, I should change my pattern to:

M/W/F - 25ml KNO3, 5ml kH2PO4
T/Th/Sa - 1/16 tsp k2so4, 10ml CSM+B, 2ml Iron

Leave CO2 alone (where it is at right now) and get the fertz stable first.

 

[Philosophos]

Ya, that should do it. I did a bit more precision calculation for those values and I'd say 1/8 K2SO4 wouldn't hurt; 24ppm vs 18ppm. If CO2 gets worked over thoroughly but K+ holes keep showing, an extra 1/8 per week may be needed. This would be the exception though, not the rule.

For the KNO3 mix, 17ppm should do it in most cases (25ml) but 30-35ml would put you in 20-24ppm range which is about the most a tank will suck up, and food will provide excess. In your case I'd tend towards 30-35ml; it'll add some extra padding.

I re-read your OP. Turn up the CO2; push it to a light green if you can. Back off if the fish start breathing heavy, and try again another day. This is the most you can do right now with all the other nutrients shorted, but it will help. Once the plants are growing properly, they will provide a better response for you to gauge your CO2 by. If you are expending CO2 too fast for your likes, try looking at other methods of diffusion and working on better distribution.

-Philosophos

 

[WarDaddy]

THANKS!

I can not even find the words.

 

[WarDaddy]

Thank is looking pretty nice.

I have a few holes in some of the leaves on my plants, but I suspect that is par for planting a new tank.. Several plants "melted" but are growing new leaves at a nice clip. Several plants have grown more than 2 inches since planting.

My CO2 system is looking good. I estimate about 3 BPS give or take. My drop Checker is looking green, way more green than the bright blue when I changed the water yesterday. The combination of the CO2 reactor I made from my PhosBan reactor and my DIY sealed return chamber in the sump, I think I am outgassing much less CO2.

I made my sealed return chamber by taking a $3 Plastic cereal holder from Dollar Store and cutting a hole the diameter of my return pipe in the top. Squeezed my return pipe in it, put my filter sock in the holder, and drilled holes in the bottom for the water to enter the sump from. I see no bubbles entering the sump now, so that seems to be helping to rediffuse co2 in that little chamber. Seems to be working like a charm. On the next water change I am going to drill a few more holes, but all is well.

I am using the modified Fret schedule from above. Time will tell on that one, just started a few days ago.

Thanks everyone!