This article is from a german forum for aquatic plants and aquascaping.
http://www.flowgrow.de
There are some serious plant experts there with a lot experience, so i think it can be trusted.
I have translated it with google translator...not the best english, but i hope it is understandable:
H202 (hydrogen peroxide) is an ideal tool for algae control, because unlike all the other chemical methods, it leaves no harmful residue… it simply breaks down into water and oxygen. A further advantage is that in the aquarium H202 decomposes fast.
Typically, a 3% solution is active against:
# Green algae
# Cladophora
# Blue-green algae
[Although a principle activity against various red algae is also there, Excell has proven to be a more reliable alternative]
The main application area for H202 (the solution is heavier than water, it "sinks") is the control of bottom near algae and infestation between ground substrate, etc.
Spot treatments should be calculated properly, so that sensitive livestock won’t get harmed. A total concentration of H2O2 in the water must not exceed 5ppm.
Only in the case of less sensitive livestock it can be increased accordingly.
3% H202 calculation:
1.) XX ml H202 (3%) * (30/ volume of aquariumin liters) = H202 ppm concentration (in water)
Or in the reverse case to calculate the required amount by ml concentration X in the water column to reach the max. recommended 5ppm with sensitive livestock):
2) H202 desired ppm concentration * (liters aquarium/30) = ml required
Spot treatments with hydrogen peroxide:
Switch off pump / filter, calculate max H202 dosage (using the formula 2) for your aquarium and dose appropriate amount and spread evenly with a syringe, inject directly on algae.
Safety Note: Do not spray on animals!
Switch on pump/filter after one hour. (In sensitive plants earlier)
Perform the process 1x daily over a period of 3-4 days.
Most algae die off, however, the effect is not seen immediately. It usually takes 7-10 days to dissolve the algae.
Only at very stubborn algae (Cladophora sp.): repeat the process with a break of 2 days inbetween each 3-days- treatment.
Note: Do not apply for species such as Riccia. Sensitive species may suffer damage or brown spots. Mosses are very sensitive (eg, coral moss).
Gross overdose and careless handling can damage animals and filter bacteria.
Complete treatment of an aquarium with 3% hydrogen peroxide:
Not recommendable, because depending on conditions (flow, light, etc.) the concentration degrades differently in the water column. Due to the properties of the peroxide solution it does not apply properly in higher regions, especially not near the water surface. It is therefore recommended to collect as much algae as possible manually and trim the plants partially.
Safety note: A complete treatment should be first carried out in a non-stocked tank. During and after a complete treatment, nitrite is to be monitored.
Here is a brief overview of what type of algae you can fight with what concentration:
1. green algae: 16-24ppm (due to the large number of green algal species may be different in tolerance)
2. Blue-green algae: 5-12ppm possibly (higher, if necessary)
This is calculated for 3-4 days, 1x daily.
It is important to simultaneously remove the causes for the growth of algae immediately. Not doing so, the treatment will have little success.
H202 + Excell combination:
In very severe cases, and when many different types of algae are present, one can also combine H202 with Excell.
The advantage of such treatment is that the H2O2 minimizes the oxygen-consuming effect of Excell, because H202 emits oxygen.
Security Note: All information without guarantee! May vary, depending on conditions.
Potential plant damage beyond 16ppm H202 in water.
Compatibility based on experience:
Plants, which can tolerate H2O2 without damage:
Rotala H´ra
Rotala Nanjenshan
Rotala Bangladesh
Rotala Occultiflora
Rotala Mex. Goias
Rotala Araguia (Cuphea)
Rotala Pussila (Mex. A)
Rotala Indica
Rotala Wallichi
Rotala Macrandra Mini Type II
Rotala Macrandra Mini Type III (Green)
Rotala Macrandra Mini Type IV (Red)
Limnophilias vietnam mini
Ludiwiga Arcurata
Taxophlyum Moos
Barbula sp. Milimetermoos
Fissidens Fontanus
Hemanthius Micromanthem
Didiplis Diandra
Ludwigia Arcurata
Lysmananchia aurea
Echinodorus bolivanus
Sagittaria subalanta
Microcarpea Minima
Micromanthem Umbrosum
Nesea Triflora
Staurogyne Repens
Mayaca Fl.
HCC
Marsilea sp.
Little damage:
Rotala Vietnam
Dwarf Riccia
Rotala Yia Yao
Rotala Macrandra Mini Type V aka. (Butterfly)
Severe damage:
Elatine Triandra
Rotala sp. Pink
Coral moss (especially with direct application of H2O2)
Total loss:
Riccia fluitans
Inverts:
RedFire Ok
snails Ok
seed shrimps Ok
Hydra Ok
Toxicity-LC 50 value:
Daphnia pulex 2,4ppm 48h
Dreissena polymorpha 5.0ppm 56h
Daphnia magna 7.6ppm 24h
Pimephales promelas 16,4ppm 96h
Physa spec 17.5ppm 96h
