Little problem (was minor disaster - not any more!)

[worley]

I use a re-circulating algae scrubber, basically, got a sump in the attic/loft room of our house, with the tank in the floor below, I have a pump sucking (not pushing) the water from the tank downstairs to the sump upstairs that has a separate pump for the ATS and a water heater. It only pumps water between the tank and the sump at 6l (1.6US gal)/hour.
A few days ago I got two new fish, from the same shop I got my first two black percula clowns from, none showed any signs of problems, but a day later (Monday) both the copperband and the blue cheecked goby had ich.
Very stupidly, I didn't quarantine them, and worse, I dug around the many bottles of parasite treatments I had that I kept hold of from having the shop... All of them said they weren't invert or algae safe, apart from Seachem Para Guard, which didn't have any warnings at all on it. So they said to put carbon in the tank straight away, which I've done. A day later the tank looked like normal.
Again, stupidly, I put a single dose in the tank, and 2 minutes later all the corals closed up and looked pretty bad, so I instantly called seachem who said they don't market it as invert safe (they should really write it on the label!!!), but that lots of people have used it with inverts without a problem.
Yesterday I noticed in the upstairs sump, where the ATS is, there was foam in the water, which started to worry me, and today the water in the sump is cloudy, so I'm pretty sure the algae on the screen is dieing which is causing the foam in the sump (but not in the main tank), and this morning most of the corals/inverts didn't look great.
So I've taken the screen out and very little wanted to come off by running my hand over it, but I've rinsed it down with a shower and a bit did come off, it does however smell a bit.
I've had to restore to using a bit of Seachem prime to counteract any ammonia/nitrite spikes, so, unfortunately, this will affect my nitrate readings (as it will reduce them).
Luckily, however, the singly dose of Para Guard seems to have wiped out the ich that only appeared for one day overnight. Very weird, never seen it come/go so fast.
This may set back the progress of my ATS a week or two :(
All in all, looks like most ich/parasite treatments are very bad for algae.
Should I do my first screen scrape with a credit card or similar, just to try and stop any more die-off?

[SantaMonica]

I have not heard of algae causing foam, dying or not. I think it's the additive. The screen is probably not harmed at all. Some folks are pouring their kalk top-off directly on it to kill pods and top-off simultaneously, with no bad effects. Why not just keep it running, and do a 1/2 cleaning.

[kcress]

Yikes. Sorry to hear..

[worley]

The odd thing was that the foam only happened in the sump with the ATS and not in the main tank.
Still, a very light clean (rubbing my hand over the screen for the first time and almost nothing came off, so I hosed it down with the shower and a few bits and a little slime came off), and 6 hours later the water in the sump has nearly cleared up, hardly any of the slimy foam left and the tank is looking fabulous again, inverts looking better than ever!
Maybe it was some of the cyanobacteria rather than the algae dieing off, still, very easy fix and looking great now, plus I got my copperband feeding at last, all good in the end! :mrgreen:

[worley]

Oh and it's probably only put the growth back 2-3 days from what I can see now, as little came off.
Remember that the sump also only has 6l(1.6us gal)/hour pumping through it and a 1200lph (317 us gal/h) pump over the screen, and the water falls very nearly into an even sheet, so the surface of the water hardly moves, it's probably acting like a skimmer.
I guess it may be a good idea to put a power head in the sump?

[kcress]

Skimmers work on foaming action. I wouldn't think it's acting like a skimmer. I wouldn't add or change anything after that brush with disaster. Leave you stressed creatures to recover before doing anything to tip the system.

[worley]

That what I meant, the fine bubbles coming off the bottom of the screen were probably acting in the same manner they do in the skimmer, and the surface of the water isn't moving as there's only 6l/hour coming into the sump, so the foam is collecting at the surface of the water in the sump, if I put a powerhead in there it shouldn't happen as it'd get disolved back into the water