Don't be afraid of my duck!
I recently switched to a "low" light setup consisting of mainly crypts, ferns, mosses, anubias and Najans indica as the sole stem plant. Substrate is ADA Powersand and Africana Aquasoil. The tank is 48 gallons, with 36x2W CF tubes switched on for 11 hours daily plus an Eheim 2242 filter. Temperature is 26-27C, pH circa 6, KH unknown but probably quite low, CO2 I reckon to be 20-23 mg/l. Fishload moderate, mostly small anabantoids, rasboras, barbs and shrimp. The tank was set up in early June.
What I have been doing is dosing KNO3 (10 mg/l), KH2PO4 (2-3 mg/l) and K2SO4 (30+ mg/l) with weekly 40-50% water changes. Traces and Fe come from 7-8 ml of Mallick's Lushgrow Aqua. Thing is, for the last two weeks, BBA has been rapidly spreading on the mosses and ferns, and I can't seem to pinpoint the problem. This week, I decided to test the water mid-week, and found NO3 to be 5 mg/l and PO4 0.25 mg/l. So it seems the macronutrient consumption rate is higher than i thought. But is this due to the use of Aquasoil (which reputedly "sucks" in nutrients from the water column into the substrate level) or because the rooted crypts are heavier feeders than I thought? One forummer suggested raising macro dosage while reducing traces (to starve off the algae and give the plants a boost) ... so I am trying this, but it's too early to tell...
Could anyone shed some light on this??
Budak:
I also experience high nutrient usage in my high-lighting (3.6 W/g) biotope tank. That NO3 and PO4 fell to levels same as yours. And experience BBA.
Now weekly I dose 10ppm NO3 and 0.75 ppm PO4 twice a week to keep the levels higher. Problem seem to be better controlled.
I would suggest you continue the Aqua levels. Good luck.
koah fong
Juggler's tanks
Budak, are you using a pH test kit for measuring pH? I find those test kits not suitable as you would need as much precision as possible in order to find your proper CO2 level. Maintaining KH seems to be a major problem with aquasoil as I have experience with it. I add baking soda to the tank and the KH shoot up to 3dKH for the first half of the day...then it went down slowly and back to less than 1 in 1-2 days. The main factor here is the peat....try getting a sample of tank water and aerate it with an air pump. Measure the KH of the sample and the pH (pH testing best done with test pen). If it reads more than 5ppm, just deduct the amount of CO2 calculated by 4ppm. Using the excess CO2 value found, deduct it from your CO2 reading at pH 6 and KH 1? See if it is still in the 20-30ppm range. You need the CO2 to remain stable in the range during light hours in order to avoid stuff like BBA and other types of algae with good fert regime of course.
Remove as much BBA as possible and add some SAEs
Fert regime with weekly 50% water change
1/2 tsp of K2SO4 after water change only
1/2 tsp of KNO3 1X a week
4 rice grains of KH2PO4
Traces...Aqua contains NO3 as well..so you might consider other type of traces or use aqua to dose NO3 and traces together...kinda inflexible though.
CO2- 20-30ppm at all times during light period (Nothing works well if this is not fixed!)
One more thing...do not trust the test kit!
Plant Physiology by Taiz and Zeiger
PeterGwee.. May I know how you calculate the CO2 in the water? Thanks..
Plant Physiology by Taiz and Zeiger
Could it be your high PO4 is causing the rapid uptake of NO3 and the other nutrients? If Aquasoil is indeed sucking up the nutrients, wouldn't it be for the roots of your plants eventually? I doubt you can go very low for TE since you are using Aqua. I would probably lower PO4 to 1ppm to slow things down instead.----------------
On 7/20/2003 11:42:11 AM
What I have been doing is dosing KNO3 (10 mg/l), KH2PO4 (2-3 mg/l) and K2SO4 (30+ mg/l) with weekly 40-50% water changes. Traces and Fe come from 7-8 ml of Mallick's Lushgrow Aqua.
----------------
When lighting level is low, plants will depend more on rich substrate for nutrients. They are less dependent on water column for nutrients compared to higher lighting.----------------
On 7/20/2003 11:42:11 AM
I recently switched to a "low" light setup consisting of mainly crypts, ferns, mosses, anubias and Najans indica as the sole stem plant. Substrate is ADA Powersand and Africana Aquasoil. The tank is 48 gallons, with 36x2W CF tubes switched on for 11 hours daily plus an Eheim 2242 filter. Temperature is 26-27C, pH circa 6, KH unknown but probably quite low, CO2 I reckon to be 20-23 mg/l. Fishload moderate, mostly small anabantoids, rasboras, barbs and shrimp. The tank was set up in early June.
What I have been doing is dosing KNO3 (10 mg/l), KH2PO4 (2-3 mg/l) and K2SO4 (30+ mg/l) with weekly 40-50% water changes. Traces and Fe come from 7-8 ml of Mallick's Lushgrow Aqua. Thing is, for the last two weeks, BBA has been rapidly spreading on the mosses and ferns, and I can't seem to pinpoint the problem. This week, I decided to test the water mid-week, and found NO3 to be 5 mg/l and PO4 0.25 mg/l. So it seems the macronutrient consumption rate is higher than i thought. But is this due to the use of Aquasoil (which reputedly "sucks" in nutrients from the water column into the substrate level) or because the rooted crypts are heavier feeders than I thought? One forummer suggested raising macro dosage while reducing traces (to starve off the algae and give the plants a boost) ... so I am trying this, but it's too early to tell...
Could anyone shed some light on this??
----------------
My take will be to ease up on the water column fertilising.
On a second look, it seemed that those plants that you have problem with are not rooted to the substrate. The uptake at low lights should not be as fast as that with high light. So nutrient shortage may not be the problem.
Test kits are known not to give precision reading. So the values you have there may not be that accurate. I suggest that you test before and after dosing and at the end of the week before water change and see if the readings make sense.
Just my opinion...
BC
mines a relative high light tank and I haven't been bothering too much about testing it.
there's bba all over my once pretty moss, I intend to peroxide it some time later.
likewise, I suspect a po4/no3 imbalance here, I've certainly upped the co2 dosage initially but it doesn't seem to be the case. this all started with the hot april weather, which probably upped the plant metabolic rate and caused all this mess.
however, bba doesn't really die in your tank. so it'll probaebly be there forever. I'm tempted to fish out the lifestock and peroxide the tank itself.
the blyxa i got recently is also melting/disintegrating..
99.5% of the BBA issues I've seen revolve around one issue, CO2, not enough of it namely.
You need to test and see about getting a stable KH.
The peat will soften the water some but after a month or two this will be reduced.
A narrow range pH test say 6.0 to 7.2 should do the trick. pH probes are great and easy to use, flip a switch and iut tells you to 0.01 units. but with a Nice price tag.
Low light tanks will suck a large amount of nutrients actually. Uptake is certainly slower but when the GH/N/P/K and the traces are in good shape, plants do very well.
These are somewhat dependent on fisg loads and feeding routines/food type.
If the tank is less than .5w/L once a week should do.
More than this, 2x a week up to about .8w/Land higher which need 3x a week if well growing.
I also do a mega dose the day before,(12 hrs or so) before my weekly 50%+ water change.
I add 2x the amount of NO3 and PO4(No trace or K+) I normally would.
This is in addition to the 3x a week.
Folks can do this megadose with any light set up.
While roots can potentially supply all the nutrients to the plant at low(er) light, the plants will prosper more by having them in the water column as well.
The ADA aquasoil might bind some nutrients but not that much for months/years on end.
Regards,
Tom Barr
Don't be afraid of my duck!
After some off-forum discussion, I get the feeling that CO2 (or lack of it) isn't quite the problem... I don't have proper pH tests so am just using my Bioplast indicator as a gauge, but the indications are that CO2 is in excess rather than surfeit (with plants like Bolbitis pearling by mid-morning). Having reread the old APD thread re: Neil Frank, I somehow suspect that the BBA is thriving DUE to the CO2 - so this week, to test the hunch, I am reducing CO2 by at least 50%, while keeping traces addition to a minimum (Ideally I would like to inject Fe into the subsrate but the effort deters me). Macros will be added at the next water change at the coming weekend. KH is also being raised (by 1-2 O). Let's see how it turns out - fingers and toes crossed.
Budak, you are going in the wrong way!!!! Algae are plants as well...if you limit algae, how about the plants? Algae have lower biomass and require less nutrients..plants require so much more than algae. Think carefully..
Having good CO2 at early part of the day but lower CO2 later can be an issue vice versa. You need to get the CO2 in the 20-30ppm range during the entire light period and not just a couple of hours. Inconsistent CO2 levels are what some algae love...they are always there waiting to strike when the conditions are not right for the plants. If you are spending on those CO2 indicators, why not get a pH test pen and get it over with. Much more worth the money then something that won't give you immediate readings (is there any reading even?).
Plant Physiology by Taiz and Zeiger
Don't be afraid of my duck!
I have almost no fast growing stem plants.... in fact I could probably do without adding CO2 altogether, just that the old habit dies hard and I want the accelerate growth that at least some injected co2 permits... blasting more CO2 (until my shrimps KKK) hasn't worked for me... let me test the idea for a couple of weeks... and see how...
Plants I have in a little 5 gallon tank (java fern, mosses, pellia and a lone barclaya) in my bathroom, with a little sun and zero fert/CO2, and virtually no water changes, are doing wonderfully, and any algae covered ferns I put in there clear up quickly..... maybe this is the way to go....
Okay, that is if you insist...try it..let us know the final result. []
Plant Physiology by Taiz and Zeiger
Hi Tom, I remembered your posting on APD about your theory of photorespiration inhibiting algae.
Photorespiration (PR) occurs in plants/algae in the presence of O2. PR effect is particularly pronounced in high light setups where O2 are most of the time close to saturation.
However, in low light setups, I would expect O2 level to be signifcantly lower. Photorespiration occurs to a lesser extent especially with CO2 injection (higher CO2:O2 ratio). Light level may be limiting the photosysnthesis and injection of CO2 may not result as much increase in O2 production as in high-light setups. On the other hand, the injection of more CO2 may even reduce the impact of photorespiration in algae.
Thus, if the PR theory is true, it seemed that it will not help in low light setups.
In many low light setup, we do no have CO2 injection (like Diana Walstaad's setups). In these setups, we can have a BBA free tank without CO2 injection. What is keeping the algae away in this kind of setups?
BC
BC, I think those low light setups that you mention with no BBA are usually PO4 limited..(not in excess but no danger going to zero due to slow uptake). BBA seems to like high phosphate.
Plant Physiology by Taiz and Zeiger
Peter, in lower lighting, plants wll be more dependent on roots system for nutrient uptake. P and Fe are 2 of the nutrients that plants can uptake via roots.
I think Budak's direction to reduce the fertilising is exactly that.
BC
Budak,
Is your barclaya doing well in the low-light tank? Mine were only growing on their reserves and, by the time I realised it, 2 of 3 died. They were in my low-light tank (1W/gal). The only one I managed to rescue is currently in my high-light tank (4+W/gal).
Suggestion : Why not put in a 'mini riccia nursery' if your low-light tank has CO2 injection? My mini-riccia can double in volume every 2-3weeks when I let them float in a confined space in my low-light tank. This stuff is so easy to propagate that I have no idea why LFSs are still charging exorbitant prices for each miniscule mesh.
With a nursery, maybe you can soak up the excess CO2 AND help bring down the price of mini-riccia.
ThEoDoRe
Mmmmmm...I did hear from Tom that plants would take in nutrients from the water column rather than the substrate as it is easier. It is only when the water column is limited in nutrients or depleted will the plants dig deep into the substrate to look for nutrients.
Plant Physiology by Taiz and Zeiger
There has been studies and even Tom has said that: lower light ---> tendency towards root uptake.
BC
hello budak,
you seem to think that you have more than enough CO2.
Using peat will lower the pH. if you're using the pH KH table to measure CO2 levels, then your readings will be inaccurate. your CO2 level will be higher than the "true" level. in fact, you might be short of CO2.
if i were you, i'd remove the peat.
your test results show that your tank's nutrient uptake is faster than expected. i think you should dose more times per week to maintain good nutrient levels.
i managed to stop BBA in my tank. i did it by keeping high CO2 levels and nutrient levels.
hope this helps.
Wayne Wah
Posting Permissions
Reply With Quote
Bookmarks