Calcium Test

Lachlan

I took my water into the lfs to see where my calcium was at. They only had a Red Sea brand marine calcium test, so I don't know if it worked on freshwater. If you're not familiar with the test, basically you put in one reagent that turns pink after twenty seconds, then you titrate until it's orange again. Well, my water never turned pink in the first place, so I don't know if that means there's zero calcium in it or if the test just doesn't work for freshwater. I tested both my tap water which is softened and my hose water, which I know comes off the water supply before the softener and should be very hard, and both had that same result. My GH is at 5 dH. Has anyone had success using this test for freshwater?

Jay

That test kit is for saltwater.

Are we talking well water here? If not, you can call the water company...ask nicely, and they will usually give you a more detailed water quality report then they are required to send out.

It would also be good to know how your water softener works. Is it ion exchange with Na being traded for Ca, is phosphate involved etc?

Jay

Lachlan

Well that's the answer I was looking for, to see if it's not a good test for fresh water. I guess I should say the reason I'm looking at calcium is because my NO3, PO4, and K all seem to be ok, so I'm looking at other deficiencies leading to my plants crapping out.
My softener works by exchanging 2 K+ ions for every Ca2+ or Mg2+ in the water. Here's the data for my pre-softened water:

pH: 7.5
GH: 22 (390ppm)
KH: 19 (340 ppm)
NO3: 0
NH3: 0
NO2: 0
PO4: 0
K: unknown

And my post-softened water

pH: 8.0
GH: 2 (36ppm)
KH: 18 (320 ppm)
NO3: 0
NH3: 0
NO2: 0
PO4: 0
K: unknown

And my tank water, as of today:

pH: 7.5
GH: 5 (90ppm)
KH: 9 (340 ppm)
NO3: 10-20 ppm
NH3: 0
NO2: 0
PO4: 2-5 ppm
K: unknown

I don't know if this math is right, but since the softener drops the water from 390ppm to 36 ppm hardness, and it replaces each Ca2+ or Mg2+ ion with 2 K+ ions, does that make for 700ppm K+? That sounds too high, but I don't know another way to calculate it. Since I'm not sure about potassium input from the tap water, I dose with API Potash/Iron solution once a week just to be sure.
I drop the 320ppm of KH to 160 ppm with Seachem Acid buffer, about 2 Tbs per 15 gal.
I have no idea how the GH goes up from the tap to the tank. I dose with flourish weekly but that has very little calcium/magnesium. I do have some mystery rocks that came with the tank, they're black, heavy, and pocked. My substrate is 100# of ecocomplete, which I don't think should add hardness.
I don't have CO2 injection, but I do add excel every other day. I tried going to every day and doing flourish 3-4x per week, but the added nutrients didn't seem to help my pathetic plants any, so I dropped back down.

Jay

OK now we are getting there...

A few more questions.

What exactly do you mean by your plans are pathetic?

What is the light source, wpg, k-temp, and duration.

Jay

Lachlan

I have 2x65W 10,000K CFs and 2x65W Actinic CFs. It's a 90 gal. tank so that's about 2.9 W/gal. I have all bulbs running for 10 hrs/day, and the actinic ones run for an additional hour on either side. It's in a room with a lot of east-facing windows, so it also gets some sun, but that's usually before the lights turn on.
Plants are pathetic because they are not growing. The inventory right now is:
4 stems of anacharis
4 swords (mix of amazon and brazilian, maybe argentine, I forget)
3 grass-like plants I got at lfs, forget what they are
1 aqua fern

The anacharis are the least pathetic, in that they actually show new growth, althought the old growth is very dark.
I bought the swords several months ago. They're still alive and seem to have big root systems, but they are puny in size. Leaves are long and skinny and don't get very big. Oldest leaves seem to have something on them, maybe brown algae? Grass-like plants don't exhibit any new growth, the ends of the old leaves are brown and frayed. The aquafern I got at the same time as the swords, and it just gets smaller.

Jay

Sorry for the delay in posting

Your tank water parameters look good to me. I am not a fan of "buffers", but I do trust Seachems products.

You could try adding peat to your filter (peat will lower GH) the down side could be a brownish tint to your water.

Personally I would use a mix of RO water and Tap water to arrive at a GH KH level that is close to 6 /4. and then supplement with a GH booster. I think that would eliminate your worries about Ca and Mg.

IMO your PO4 is a little high for the plant mass you have in the tank. 1ppm would be sufficient.

Some other heads up and FYIs

Seachem Excel is a great product, however there are some plants that react poorly, anacaris being one of them. The fern could also be suffering.

Sword Plants are heavy feeders of NO3 and PO4 and require a rich substrate. Unless you have established a consistent water column dosing routine, you may want to supplement with a plant tab under the Sword.

The watts per gallon "rule of thumb" assumes high intensity full spectrum fluorescent light.

Actinic lights while great for saltwater corals are of dubious value for plants. They will not hurt you, but they really do not help much. This is perhaps another factor in you plants doing poorly.

If your light was really in the 2.9 wpg range (it's not after factoring out the blue light) , you need to be dosing Excel every day or consider injecting CO2.

Jay

Lachlan

So do I need to swap out the actinic lights for another pair of 10k's or could I expect plants to do well with the lights I have?
Also, I thought having a substrate like ecocomplete meant not having to add tabs. Why doesn't ecocomplete do the job? Also, if there's still nitrate and phosphate in the water, why would the swords need further supplementation?

I'm not a hard-core planter or anything, I just want to get a nice planted tank started and living in harmony with the fish. Are there some other species of plants that I should be considering for my situation?

Thanks,
Lachlan

Jay

IMO you need to be at 2wpg of full spectrum fluorescent light. Sword plants could use a little more 2.5+

The Eco complete is mineral rich plus has iron that is available to plants. If not enough light is being supplied to the plants for photosynthesis they will not be able to uptake the available minerals and will go into decline.

Consistency is the key to providing NO3, PO4, and Potassium, plus a GH with a good ratio (4:1) Ca / Mg never allowing one to bottom out or become a (limiting factor).

Carbon is an important issue...plants are up to 60% carbon by dry weight. Without CO2 injection I would dose Excel every day. Eco-complete will not give you carbon.

Jay