Hypo in large tank

[Tat2demon]

I had to move all my fish four different times in a week due to tank repairs and all that stress has brought out a good case of crypto that I thought I had previously gotten rid of with Crypto-Pro.

Im not going to put them through another move so I plan on doing hypo to my entire 418. I know its best to remove sand and rock but at this point thats really no longer an option.

How big of a problem is this going to be?

 

[MrTuskfish]

You sure aren't the first person to think Crypto-Pro worked; it seems to be an effective med; but is impossible to keep in suspension, assuring an effective dose. (Info from a few tech people)
Hypo is always "iffy", IMO & IME. A perfectly calibrated hydrometer is a must. Pay close attention to water level; just a days evaporation can bring the SG up enough to ruin the treatment. An ATO is a big plus. Putting the fish through another move won't hurt them; but its a PITA, I know.

 

[discocarp]

The hypo will kill just about everything on the rocks and sand. You will likely have a huge ammonia spike and probably end up killing your fish if you go this route imo. Unless it is pretty fresh dead sand and rock with no life on it I would strongly suggest you do not go this route.

For the record, I don't think hypo is 'iffy'. I've had perfect (100%) success with it. I agree you need a good hydrometer or salinity meter and need to watch evaporation very closely.

 

[Haffs09]

I tried hypo unsuccessfully twice on a ~425 gallon system. I was at 1.008/1.009sg for 6 weeks the first attempt and 8 weeks the second attempt. I don't have a sandbed, but did have 300lbs of rock in the system. Some of it was relatively new (200lbs) and 100lbs came from an established tank. I religiously changed 10% of the water every 3-4 days to stay ahead of any ammonia spikes. I think my failures may have been caused by:

1. Taking 10-12 days to get down to 1.008 vs. the two recommended days. I was constrained by my RODI output. I suspect taking that long could have allowed some of the parasite to adapt to those conditions and although all the fish looked good after the treatment, it took 4-6 weeks before it came back.

2. I never calibrated my refractometer at 1.008 s.g. It read consistently when I compared it to a friend's at normal salinity levels, but maybe there was drift at the lower levels? I don't know as I never compared it when at the lower levels.

After the second failure, I pulled all the fish, treated with cupramine and ran RODI water through the system for 4 weeks. Of the three surviving fish (foxface, desjardini and hippo tangs), I still have them in a separate 75gal tank. I added a QT'd achilles to that tank 6 weeks ago to act as a "canary in the coal mine." So far, all fish are ich free and it will be another six weeks before I return them to the display tank. The main system has had new fish (put through a thorough QT process) in it for the past 6 weeks, and they're all doing excellent.

Good luck!

 

[MrTuskfish]

For the record, I don't think hypo is 'iffy'. I've had perfect (100%) success with it. I agree you need a good hydrometer or salinity meter and need to watch evaporation very closely.

Yeah, "iffy" wasn't the best choice of words. I just meant that there is a lot of room for error and has to be done very precisely.

 

[Andrew]

Hypo just requires a lot of work and checking. I've always had perfect luck with hypo but I keep the salt in my hypo tanks a little under 1.008. Hold there for 6-7 weeks and you'll be in business. Never had an issue but if you even let the salt rise a little bit than your taking a risk at messing up the whole process which is the case for most people.

 

[Tat2demon]

Thanks for the input guys. I have a calibrated refractometer and its a fully functional system including ATO. I drained a good amount of water last night and am letting my RO unit fill it back up over the next couple days.