Beginners Info Sheet
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Tank Dimensions (LxWxH): 4' x 1.5' x 1.5'
Tank Volume (litres or gallons): 250L
Lighting Intensity(No of Watts) : 216
Type of Lighting (FL/PL/MH) : 6 x 36W PL (1 year old)
No. of Hours your light is on : 8
CO2 Injection Rate (bps) : 3
Type of CO2 (DIY/Liquid/Tank) : Tank
Method of Injection (e.g. Diffusor/Reactor): Reactor
Substrate Used : Denerle Crystal Quartz
How Thick is your base fert : 1"
How thick is your gravel : 2"
Liquid Fertilizers Used : Seachem Flourish, K2SO4, KNO3
Frequency of fertilization : once a week
Tank Temperature : 28-30 degrees
Type of Filter (overhead/internal/canister) : canister
Filter media used : ceremic rings and sponge
How long has your tank been set up : just finish rescaping the whole tank
Other equipment :
Chemical Properties (Fill what you can)
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Carbonate Hardness (KH): 3
Total Hardness (gH): 4
pH : 7.9 (before CO2 and lights), 7.5 after 1 hr of CO2 and lights
NH4 (ppm): ??
NO2 (ppm): ??
NO3 (ppm): 12.5mg/L (before CO2 and lights)
PO4 (ppm): ??
Fe (ppm): ??
Bioload (Your Fish and Plants)
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50 x Cardinal tetra
1 x rainbowfish
5 x SAE
12 x yamato
3 x oto
Describe your problem :
Manually removed all the hair algae and do a complete rescaping (all plants replanted) of the tank. Did a 70% water change and dosed 3ml of seachem flourish and added K2SO4 (using Chuck's calculator) 20ppm worth of K. Am I dosing fertiliser correctly? Will this help me control the algae? If I'm upgrading to MH lights, will 4x75W or 2x150W is better?
Fix your CO2 before you even talk about fertilization....Your plants are not going to use up much nutrients if the carbon is limited. Get the pH down to within 6.4-6.6 using CO2 only. It should take half or at most an hour or so to drop the pH to the range and keep it there throughout the entire photoperiod.
Plant Physiology by Taiz and Zeiger
Like what Peter said, something is very wrong with either your CO2 or pH reading. With that amount of CO2 being injected (and i assume it's dissolved properly), pH should be in the mild acidic range. Plants in general doesn't like alkaline water. So check if you have any buffering stuff added in the substrate or filter media and remove them if you can. You might also had been adding too much baking soda or coral chips.
As for MH, if you are planning to get the pendant type from lighting shops, I would think it's better to get 2x150W. The main reason is the size of the pendant. IMO, with 4 pendants above the 4', it would look a little too cramp.
I think the light setup is fine...adding more light is going to cause more problems if the CO2 is not fixed. Once that is fixed, adding ferts is pretty easy. Strong growth is what you should be targetting before thinking about getting the redness of red plants out...
Plant Physiology by Taiz and Zeiger
Thank you Peter and oqs. Just measured the pH after dinner and it has dropped down to 6.9 (pH pen) and kH of 3. From CO2 chart, CO2 should be about 15ppm which is a nice figure eh? BTW, it happens only when I increase CO2 to 4bps.
Get it down to 6.4-6.6 instead..error on the higher side and make sure it stays in that range throughout the entire photoperiod and not just at the start or end of the photoperiod.
Keep a close tab on the CO2 for now and make sure you had it nailed pretty good before you can go on to fertilization. Slack on this and the results would not be good. I went through it and I know the difference it makes. 20-30ppm is what you should be targetting at..I go for the higher side as errors from readings might indicate a higher CO2 count but in fact it is lower.
Plant Physiology by Taiz and Zeiger
Before you continue to increase the CO2 level, what plants do you have? That's important information to help you decide whether you should change your light setup. My suggestion to you if you are getting light and nutrients hungry plants, it's good time to change your 1 year old tubes. IME, PL tubes at 1 year old had lost much of its original intensity, which might cause problems and inbalance if you continue to increase CO2 without maintaining the light intensity.
What imbalance?
Plant Physiology by Taiz and Zeiger
At low light, my concern is the rate of photosynthesis will slow down, meaning less CO2 used up and the concentrations might build up over time. This might be dangerous for the tank's inhabitants. IMO, light and CO2 should be kept in balance for the tank to be healthy and algae free. Do you mean even if there is slowed plant growth, excess nutrients and of course CO2, there won't be any algae? I'm not sure if high CO2, regardless of light levels, neccessary means no algae, but i can say too high and that will mean no fish [].
CO2 building up? How is it going to build up when you have adjusted it according to the uptake rate? [
Good CO2 levels at even low light levels is going to help plants as they the plant can afford to invest less energy and resources in CO2 uptake and that leaves more energy for optimising the light utilisation – more Chlorophyll can be produced without fatal consequences for the energy budget.
Strong growth of plants is going to prevent algae..thats definitely true.
Pic from Tropica Website...read up the article..good stuff.
Plant Physiology by Taiz and Zeiger
Don't be afraid of my duck!
i find that in my 3 ft tank (72 W of light), with about 30 mg/l of CO2 (which seems to work in getting BBA under control), the plants (ferns, crypts, mosses, anubias) are actually very fert hungry - i change water (30-40%) fortnightly but need to dose 2-3 times in between (NPK and micros).
Resistance is futile, you will be administrated!
Actually, it's still a good idea to change the light bulbs now. Because if you balance your fert to the current lighting and then you change your light, the balance may be thrown off again. So might as well change them now and then get the balance correct once and for all.
Thereafter, change half the lights every 6 months. Don't stinge, get the good bulbs. Osram seems to have a decent lifespan before intensities drop too much.
Vincent - AQ is for everyone, but not for 'u' and 'mi'.
Why use punctuation? See what a difference it makes:A woman, without her man, is nothing.
A woman: without her, man is nothing.
Ok, just measured the pH again this morning which is without lights and CO2, it reads 7.5 compared to 6.9 at night with lights and CO2. To reduce it down to 6.5, do you guys think that I should filter the water with some peat as filtering media? Ok, light.. thats why I'm thinking of changing to MH since the PL loses it intensity.
Resistance is futile, you will be administrated!
No no... dun use peat to lower the pH. The reason Peter is asking you to target that particular pH value is so you have enough CO2 in the water. In other words, if you inject enough CO2 to reach the pH value, then you will have enough CO2 in the water. The current recommendation for CO2 is 20-30 ppm.
Forget about bps... it does not tell you anything useful. For a tank that size, the bps is usually uncountable at the recommended level.
Vincent - AQ is for everyone, but not for 'u' and 'mi'.
Why use punctuation? See what a difference it makes:A woman, without her man, is nothing.
A woman: without her, man is nothing.
Hey Vinz, thank you for clearing my doubts. I actually managed to lower the pH last night to about 6.4 but the bubbling rate is very high (yes, un-countable) [:0]. Pressed the panic button and readjust pH went back to 6.9. Will try to achieve that pH level again later tonight.----------------
On 10/6/2003 10:33:02 AM
No no... dun use peat to lower the pH. The reason Peter is asking you to target that particular pH value is so you have enough CO2 in the water. In other words, if you inject enough CO2 to reach the pH value, then you will have enough CO2 in the water. The current recommendation for CO2 is 20-30 ppm.
Forget about bps... it does not tell you anything useful. For a tank that size, the bps is usually uncountable at the recommended level.
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Hi,----------------
On 10/6/2003 10:24:59 AM
Ok, just measured the pH again this morning which is without lights and CO2, it reads 7.5 compared to 6.9 at night with lights and CO2. To reduce it down to 6.5, do you guys think that I should filter the water with some peat as filtering media? Ok, light.. thats why I'm thinking of changing to MH since the PL loses it intensity.
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In my opinion, you should adjust your CO2 output to maintain a consistent level throughout the whole day. It is just not good to start injecting CO2 only when the lights come on.
You can still do it without a pH controller, just abit more deligence on your part, that's all. For me, I'm doing without my pH controller right now, and have managed to maintain the pH at about 6.4-6.6 range throughout the day, with the CO2 running in about 16 hrs a day.
Like what Vince had mentioned, it is not good to addd peat to lower the pH, since the primary objective is to increase the dissolved CO2 concentration in there. With additives like peat, that will contaminate your projected CO2 concentration reading, since things like peat also reduces pH, but doesn't add in additional CO2 into your water column.
In my own experience, besides your CO2 level and the lighting intensity, you may want to check your Fe level in there, as I find that an imbalance with excessive Fe in relation to other nutrients, had encouraged hair algae growth in my previous setups.
Cheers,
Kenny
I have not seen high Fe as a problem as long as the other nutrients are in good range. Folks blame innocent nutrients for algae problems when it is them who should be blame for inconsistent dosing or not dosing enough. I have pushed my flourish dosing up to 10ml 3x per week on my 50l tank with no algae problems...high Fe causing algae? Nah...your assumption of high Fe causing algae is wrong here..Fe is just traces and does not cause much harm than what NO3 and lack of CO2 can do (Why did the hair algae came in? Lack of Fe? Nope, Fe/Traces which is needed by plants only in trace bits would not cause that much of a problem as long as there are some available. Too much? Barking up the wrong tree again..Do you think you can limit algae before you start killing plants? It is the macros that you should watch closely..the NO3 is the major cause of most problems other than lack of CO2. Once the plants are stunted by lack of N, they would slow down and eventually shut down, which is when algae blooms.P
Plant Physiology by Taiz and Zeiger
Hi Peter,----------------
On 10/7/2003 1:15:51 AM
I have not seen high Fe as a problem as long as the other nutrients are in good range. Folks blame innocent nutrients for algae problems when it is them who should be blame for inconsistent dosing or not dosing enough. I have pushed my flourish dosing up to 10ml 3x per week on my 50l tank with no algae problems...high Fe causing algae? Nah...your assumption of high Fe causing algae is wrong here..Fe is just traces and does not cause much harm than what NO3 and lack of CO2 can do (Why did the hair algae came in? Lack of Fe? Nope, Fe/Traces which is needed by plants only in trace bits would not cause that much of a problem as long as there are some available. Too much? Barking up the wrong tree again..Do you think you can limit algae before you start killing plants? It is the macros that you should watch closely..the NO3 is the major cause of most problems other than lack of CO2. Once the plants are stunted by lack of N, they would slow down and eventually shut down, which is when algae blooms.)
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haha, sorry, I'm still stuck to the old school of thoughts of nutrient limitation of abt 7 yrs ago.
Er....I was able to consistently cause a hairy algae bloom with Fe at slightly less than 1ppm, PO4 <0.25ppm and NO3 at approx.5ppm.
Yup, it is a nutrient imbalance that is the root cause to all algae problem, but I just thought that excessive Fe would be the one to push the hairy algae button. Like what you've said, Fe is only required in traces, and in my opinion, at 1ppm is quite high to me.
At the end of the day, it is still easy to summarise algae bloom under nutrient imbalance, just like how we can blame genetics for almost anything, but not looking at predisposing environmental factors. There are certain nutrient, in excessive amount that can trigger certain algae blooms.
However, I think I like the current school of thought better!
Cheers,
Kenny Poh
PO4 kits are funny and are pretty uselss to me. Are you measuring organic or inorganic PO4? Plants are unable use the organic PO4 which might be what your kit is picking up.
How sure are you of your NO3 levels? Good kits or cheapo type? Running lean on NO3 and you get very nice red plants with other nutrients in good range but risk stunting your plants if they bottom out. Not all plants like low NO3 though...all plants have different ranges..its up to you to feel for it. A green plant is definitely better than a stunt plant. [
Oh, the most important thing of all in a high light tank is good amount of CO2! Slack on this and plants slow down and so does nutrient uptake. Go down the path and check thoroughly for your problems. Lights, CO2, N, K, traces and P. I had hair algae blooms before but took care of them by making sure my CO2 is good and providing a juicy water column plus weekly removal of algae during water change.
Plant Physiology by Taiz and Zeiger
Peter,----------------
On 10/7/2003 2:48:30 AM
PO4 kits are funny and are pretty uselss to me. Are you measuring organic or inorganic PO4? Plants are unable use the organic PO4 which might be what your kit is picking up.
How sure are you of your NO3 levels? Good kits or cheapo type? Running lean on NO3 and you get very nice red plants with other nutrients in good range but risk stunting your plants if they bottom out. Not all plants like low NO3 though...all plants have different ranges..its up to you to feel for it. A green plant is definitely better than a stunt plant. [
Oh, the most important thing of all in a high light tank is good amount of CO2! Slack on this and plants slow down and so does nutrient uptake. Go down the path and check thoroughly for your problems. Lights, CO2, N, K, traces and P. I had hair algae blooms before but took care of them by making sure my CO2 is good and providing a juicy water column plus weekly removal of algae during water change.
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Could you point me to any references on your remark that PO4 testkit unreliable because they measure both organic and inorganic PO4?
My understanding at this moment :
Inorganic Phosphorus exist mainly as Phosphate or PO4 and there is 2 forms of PO4 in our tank - dissolved and particulate. Dissolved PO4 is available to plants while particulate PO4 isn't.
Organic Phosphorus may or may not be available to plants in their original state but it does get converted to PO4 by phosphatase activity.
ThEoDoRe
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