Reef safe treatment for ich & velvet? Maybe......

Ich and velvet are common parasitic diseases in aquarium fish, and hydrogen peroxide (H2O2) can be an effective, albeit controversial, treatment when used correctly. This blog post provides general guidelines for dosing H2O2 to treat these conditions. Always exercise extreme caution and research thoroughly before using any chemical treatment in your aquarium.

⚠️ A Crucial Pre-Treatment Warning

Before considering hydrogen peroxide:

• Diagnosis is Key: Ensure your fish actually have Ich (white spots like salt, Ichthyophthirius multifiliis) or Velvet (dusty, gold/rust-colored coating, Piscinoodinium pillulare). Misdiagnosis can lead to unnecessary treatment.
• Quarantine: Treat fish in a separate quarantine tank if possible. This protects your main tank's beneficial bacteria and invertebrates (which are often sensitive to H2O2).
• H2O2 Strength: The dosing outlined below is for the standard 3% hydrogen peroxide solution available at most drug stores. DO NOT use stronger industrial solutions.
• Test on a Small Group: If you have many fish, test the dose on a single, less-valuable fish first to gauge tolerance.

🔬 Understanding the Mechanism

Hydrogen peroxide works by releasing an extra oxygen atom, which forms free radicals. These radicals are highly reactive and destroy the cells of the parasites. It also acts as an oxidizing agent that can increase the oxygen level in the water, which can benefit stressed fish. However, this same oxidizing power is toxic to both the parasites and the fish (and beneficial bacteria) at high enough concentrations.

💊 Dosing Hydrogen Peroxide for Ich and Velvet

 

Step-by-Step Treatment Protocol (Bath)

1. Week 1 & 2-Dose the below milliliters of hydrogen peroxide 3 times a day spread out Week 1- 1ml/8g (3 times a day), Week 2- 1ml/5gallons (3 times a day), Week 3 and onward 1ml/5g (3 times a day) and a nightly dose every 30 minutes (12 doses total of 0.166 ml/5g so in a 100 gallon tank 12 doses of 3.33 ml over a 6 hour period.

*Dosing pump recommended for overnight doses

Hydrogen Peroxide dosing chart (3% solution)
Tank Size in gallons	Week 1 3 times per day	Week 2 3 times per day	Week 3 & onwards 3 times per day	Week 3 and onwards (Nighttime dose) Every 30 minutes (12 doses total)
10	1.25 ml- 3 times a day	2 ml- 3 times/day	2 ml- 3 times/day	.33 ml - Every 30 min
25	3.1 ml -3 times a day	5 ml -3 times/day	5 ml -3 times/day	.82 ml - Every 30 min
50	6.2 ml- 3 times a day	10 ml- 3 times/day	10 ml- 3 times/day	1.6 ml - Every 30 min
100	12.5 ml- 3 times a day	20 ml- 3 times/day	20 ml- 3 times/day	3.3 ml - Every 30 min
120	16.2 ml- 3 times a day	24 ml- 3 times/day	24 ml- 3 times/day	3.9 ml - Every 30 min
180	22.5 ml- 3 times a day	36 ml- 3 times/day	36 ml- 3 times/day	5.9ml - Every 30 min
300	37.5 ml- 3 times a day	60 ml- 3 times/day	60 ml- 3 times/day	9.9 ml - Every 30 min

 

 

2. Observe Closely: Watch your fish for signs of distress, such as rapid breathing, lying on the bottom, or erratic swimming. If severe stress occurs, immediately perform a large (50-75%) water change.
3. Duration: This dosage provides a short-term, therapeutic concentration. The peroxide is quickly broken down into water and oxygen, typically within an hour, making a large neutralizing water change unnecessary unless fish are distressed. Continue the week 3 and onward dosing for 10 days longer than the last sign of any disease in your system.  So if you saw white spots on day 10 dose for 20 days total

🌡️ Increasing Efficacy with Heat (Ich Only)

For Ich, increasing the water temperature can significantly shorten the parasite's life cycle, making the H2O2 more effective.

• Target Temperature: Slowly raise the tank temperature to 82∘F to 86∘F (28∘C to 30∘C) over 24 hours.
• Crucial Caution: Ensure your fish species can tolerate this heat. High temperatures reduce dissolved oxygen, so increase aeration (airstone/air pump) significantly during treatment.

❌ What NOT to Do

• Do Not Combine Chemicals: Avoid using H2O2 with other medications, especially organic dyes like Malachite Green, as this can create dangerous and unknown chemical reactions.
• Do Not Overdose: Dosing even slightly too high can be lethal to your fish. Do not estimate.
• Do Not Treat Indefinitely: H2O2 is harsh. Stop treatment once symptoms have cleared plus 10 days. Continue monitoring for a few more days.

While hydrogen peroxide offers a chemical-free (it degrades to water and oxygen) alternative to traditional medications, its use requires careful measurement and constant observation. When in doubt, consult with a veterinarian specializing in aquatic animals or use proven, commercial fish medications.