mysterious itching

[BigBadGourami]

Hi I have a question/concern. My fish particularly the loaches and
platies are frequently scrathing the tops of their heads on objects in the
tank. I eradicated itch from the tank a month ago with salt, high heat, and
aquarisol. I didn't see spots for 2 weeks but the fish continued to itch so
I treated an extra week for ich (about a total of 4 weeks every 2 days w/
water change every 4). I haven't seen a spot in weeks. I put the carbon
back in and reduced the salt last week. They are still scratching with no
sign of ich. I assume aqaurisol would have killed any other parasites like
flukes. I also see no other signs of disease. I tried doing a scrape and
looking at it under my microscope and found nothing.
What could be causing the itching and how can I stop it.

Tank 55 gal
filter penguin 330 biowheel and a regent with only sponge
elite 802 pump/ 2 airstones
ammoia and nitrite 0
nitrate less than 20
pH 8.0
temp 80
population
3-blue 2" (3 spot) gouramis
2-pearl (2")
3 giant 3" (Colisa fasciata) gouramis
6 small platies red and red wag
3 red sword tails
4 black mollies
3 2" clown loaches
6 small danios (pearlsand zebras)

[tomatillo]

Scraping against objects when there's no parasites is a symptom of pH being
too high. A recent reservoir expansion sent our pH up from 6.8 to 7.6. When
I lowered pH from 7.6 to 7.2 by 50% water changes with distilled water, the
scraping stopped.

BigBadGourami wrote:

> Hi I have a question/concern. My fish particularly the loaches and
> platies are frequently scrathing the tops of their heads on objects in the
> tank. I eradicated itch from the tank a month ago with salt, high heat,
> and aquarisol. I didn't see spots for 2 weeks but the fish continued to
> itch so I treated an extra week for ich (about a total of 4 weeks every 2
> days w/
> water change every 4). I haven't seen a spot in weeks. I put the carbon
> back in and reduced the salt last week. They are still scratching with no
> sign of ich. I assume aqaurisol would have killed any other parasites
> like
> flukes. I also see no other signs of disease. I tried doing a scrape and
> looking at it under my microscope and found nothing.
> What could be causing the itching and how can I stop it.
>
> Tank 55 gal
> filter penguin 330 biowheel and a regent with only sponge
> elite 802 pump/ 2 airstones
> ammoia and nitrite 0
> nitrate less than 20
> pH 8.0
> temp 80
> population
> 3-blue 2" (3 spot) gouramis
> 2-pearl (2")
> 3 giant 3" (Colisa fasciata) gouramis
> 6 small platies red and red wag
> 3 red sword tails
> 4 black mollies
> 3 2" clown loaches
> 6 small danios (pearlsand zebras)