I have not been measuring my tank's parameter for a few months and recently I have been getting hair algae on 2 of my tanks. So I decided measure the water parameters..
Tank1 - 3ft - PH 6.2 KH 9 GH 14, 25 cardinals, 5 mollies, 6 cherry barbs, 5 cat fish.
Tank2 - 2ft - PH 6.0 KH 9 GH 14, 12 cardinals, 3 platies and a few cories
Tank3 - low maint - PH 7.6 KH 6 GH 16 - 12 espei, 2 platies, 1 cat fish.
I am curious why the KH and GH of tank 1 and 2 is so high and the PH of tank 3 is so high ! Tank 1 and 2 have CO2 (~12b/s), 3W/G of light and I dose NO3 and KH2PO4 twice a week.
Tank 3 is a low maint tank with no CO2 and 2W/G light. I could not get any plant to grow well in this tank. All the mosses, Anubias, Crypts, Hygrophila are stunted in this tank. Is it due to the high PH ? What can I do to lower the PH ?
I believe all 3 tanks have high PH if without CO2.Originally Posted by GanCW
Dosing KNO3/KH2PO4 could result to PO4NO3++ the Phosphates could have drive PH to high side. The high KH also raise the PH.
A 100% water change is the best but I affect your crypt, anubias and mosses may turn brown.
Use Seachem Equilibrium to restore the GH.
Tank 3 is getting some of its CO2 by plants grabbing it from the KH (mostly Ca or MgCO3/HCO3), and leaving the CaO or MgO (or CaOH, MgOH) behind. Hence KH drops and GH stays the same (or rises as evaporation concentrates it). The pH is meaningless except as an indication of how much CO2 you have present. CO2 forms a weak acid in water (HCO3) and drops pH a given amount for a given amount of alkalinity (KH). You can read the result from charts as given in the Krib.
In general, plants and fish cannot "feel" pH in the range between about 4 and 10, but are affected by some of the reactions that pH induces. The conversion of ammonium ions to dissolved ammonia (highly toxic to fish) is a classic example of the effect of high pH. Some bacteria seem unable to live in low pH water, which is a big help with some puddlefish, like wild Bettas, that have better egg and baby survival at lower pH.
The KH and GH are high because you have moderately hard water. For rainforest or Amazonian fishes, I prefer to dilute it with RO water and then use the acidic components of peat or peat extract to lower pH. The humic acids in peat are a bit too weak to work very well with harder water. The buffering of the high KH will just keep the pH high. Diluting your water with about 2/3 RO water will make peat into an effective pH reducer, without making the awful chemical soups many LFS products create. I also use only boiled peat, which is much less aggressive as either a softener or pH reducer than is the raw product. Here in the US, Canada sphagnum peat moss often has a lot of lime added to prevent burning the plant shoots and tender roots. They don't mention it on the label, so boiling and rinsing makes it sink quicker, but also rinses out the those additives that may keep it from working at all.
HTH
Wright
01 760 872-3995
805 Valley West Circle
Bishop, CA 93514 USA
What kind of substrate are you using for all 3 tanks? The GH should not get this high if you having been dosing Equilibrium or any Ca/Mg additives. Water from my taps (previous and current residences) only has GH values of between 2-4.
Thanks for all the replies.
Kho, tank 3 is without CO2 and does not get KNO3/KH2PO4 dosing. It is a low maintenance tank with just light and filter. PH is on the high side.
I only dose KNO3/KH2PO4 in Tank 1 and 2 and the PH is still low (6.0 and 6.2)Dosing KNO3/KH2PO4 could result to PO4NO3++ the Phosphates could have drive PH to high side. The high KH also raise the PH.
I am considering using peat or ADA soil to lower the PH but as you mentioned the high KH might neutralised the effect. I am not sure where I can get large amount of RO water in Singapore so RO water is not an option.
I am using the normal inert river gravels. I have not used Equilibrium or Ca/Mg. Maybe I should try it. I have no idea why the KH and GH has gone so high. It used to be lower. The only thing I change recently is I added some lava rocks in the filter and dose KNO3/KH2PO4 in tank 1 and 2.
Your critters seems fine for your tank 1 and 2? Something fishy here...check your test kits and if a pH pen is being used, recalibrate it. With that amount of CO2, all the critters would be dead by now. The amount of CO2 isn't that high as it seems. 12b/s is way too much for a 2ft and even a 3ft tank in my experience. 1-2b/s is more of a close estimate.
Do not do any water changes unless you decide to prune or uproot plants which happens only in a blue moon due to slow growth. Add some baking soda and Seachem EQ to the tank and feed the critters regularly. That should more or less cover the plants needs. If the plants still show deficiency despite regular feeding, you might add a tad bit of KNO3.
Regards
Peter Gwee :wink:
I am using a test kit. I think the kit is accurate but I will double check.Your critters seems fine for your tank 1 and 2? Something fishy here...check your test kits and if a pH pen is being used, recalibrate it. With that amount of CO2, all the critters would be dead by now. The amount of CO2 isn't that high as it seems. 12b/s is way too much for a 2ft and even a 3ft tank in my experience. 1-2b/s is more of a close estimate.
I check the bubble count again and I think it is more like 6b/s.
OK. I will try Seachem EQ. I do not dose any fert in this tank.Do not do any water changes unless you decide to prune or uproot plants which happens only in a blue moon due to slow growth. Add some baking soda and Seachem EQ to the tank and feed the critters regularly. That should more or less cover the plants needs. If the plants still show deficiency despite regular feeding, you might add a tad bit of KNO3.
BTW, is it ok to mix KNO3/KH2PO4 into a single solution ? I was lazy and mixed them into a single solution so that I can dose both chemicals in one one go.
Not even close...something is way off. Too much errors in the readings is my guess. At ~150ppm of CO2, your plants will do fine but your critters should be all dead. If they are all fine, it definitely isn't at that amount... :wink:
Just dump it in dry....no issues and much more easier. Just like cooking..
Regards
Peter Gwee :wink:
Ok, i will try another test kit.
I would love to do that but how do you measure how much crystals to dump in ?Just dump it in dry....no issues and much more easier. Just like cooking..
Hi Gan,
Go to this
http://www.csd.net/~cgadd/aqua/art_p...osage_calc.htm
Try to acheive the following dosage level (ppm or mg/l):
1) NO3 - 3~8
2) PO4 - 0.3~1.0
3) K - 10~15
4) Mg - 2~5
I am already using this calculator to prepare my ferteliser solution. I am curious how Peter measure his dry dosage ? With fertiliser solution we measure by ml for each dosage. With crystals, how do you measure ? By number of crystals ? mg ?
Gan, 1/4 teaspoon of KNO3 for a 20gallon would give you approx. 11.34 of NO3. You can scale up and down according to your tank size. Its not so precise but will do for planted tanks. The dosage 10ppm dosage is already in excess as that is based off max uptake rate for a 5.5w/g tank. If your light is lower, the uptake would definitely be less. The reason why we dose at max uptake rate is to prevent the nutrients from running out. As for KH2PO4, 1-2 rice grains per 20 gallon tank should be more than enough for 2-3 days. You can use Chuck Gadd's online calculator which you would need to enter the amount of water to mix to 1 or use the offline calculator and set it to dry mix. Using cooking teaspoons is pretty easy and dosing dry is the way for me. No mixing needed..just straight into the tank. Regarding the GH thingy, you can simply dose 1/4 teaspoon of Seachem Equilibrium to a 20gallon tank after every water change and not worried about Ca/Mg issues. Using the estimative index method would rule out all nutrient issues and if you are still experiencing plant grow or algae issues, it is definitely the CO2 (it may seem that your pH and KH reading is high but if you dose 3x per week for your high light tank at max uptake rate, you can crank in your CO2 rate slowly till you get the plant growth you want rather than trust some kit that is bad.) unless you have too many critters or lack of maintenance (did not clean filter..filter flow rate drop resulting in poor circulation.).
Regards
Peter Gwee :wink:
Example, KNO3
It is consist of 60% NO3 and 40% K. If you dose 1g of KNO3 into 100L of water, you get:
1g of KNO3
= 0.6x1x1000 mg NO3 + 0.4x1x1000 mg K
= 600mg NO3 + 400mg K
Therefore, 1g KNO3 into 100L of water will yield:
600/100 mg/l NO3 + 400/100 mg/l K
=6mg/l NO3 + 4 mg/l K
Note: mg/l = ppm (parts per million)
To measure KNO3 in volume
Estimated density of KNO3 is 2.42 g/cm3, therefore,
1cm3 of KNO3 = 2.42g
Note: cm3=mL
Tips: use the 5ml test tube from test kits to measure the volume instead of spoon and weighing machine.
Freddy,
We should be using bulk density rather than absolute density for PMDD calculations. That's why Chuck lists 5.6g per tsp (or ~1.1g/cm3) for KNO3.
What's bulk and absolute density?
When we use spoon as volume measurement, should we do it in heapful or flat?
BTW, I sceptical that the KNO3 density is 1.1g/cm3 because it sink readily/rapidly in water.
Thanks.
This is the best definition I found online so far:
... Under specified conditions of temperature and pressure, density of a fluid is defined as described above. However, the density of a solid material can be different, depending on exactly how it is defined. Take sand for example. If you gently fill a container with sand, and divide the mass of sand by the container volume you get a value termed loose bulk density. If you took this same container and tapped on it repeatedly, allowing the sand to settle and pack together, and then calculate the results, you get a value termed tapped or packed bulk density. Tapped bulk density is always greater than or equal to loose bulk density. In both types of bulk density, some of the volume is taken up by the spaces between the grains of sand. If you are interested in the density of the grain of sand itself you need to measure either envelope density or absolute density.
When using a measuring spoon, we should make it a flat heap. You should be able to get the proof for this one in cookbooks, online and off.
Even though the bulk density of a salt may be closer to 1g/cm3 (esp. when it is can't be tightly packed due to the shape), we really should be comparing the absolute density of the salt against that of the fluid. A substance will sink as long as it is denser than the fluid (e.g. water).
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