Urgent Help! ICH, ammonia spike and loosing fish! :(

try a product called kick ick- it really works very well if you follow the directions- get the big bottle- you will need it- try Premium Aquatics, they sell it. Seriously, this stuff really does work, and it works very fast. You have a pretty large bio load, so I hope you have a good skimmer, and a large fuge. Remember follow the directions to the letter.

BTW, it really is reef safe. I have used this product, otherwise I wouldnt recomend it.

 

BTW, one thing I also highly advise, use API kosher aquarium salt, this will help replace depleted minerals from water changes- you wont need to dose any thing and it will help regulate pH, there by regaining water stability.

 

So you have 4 clownfish in your 90 gallon, you used to also have 4 tangs, you currently from what i read have 21 fish in your 90 gallon, and you recently lost 3 tangs and rabbitfish?

Your tank is way too over stocked in my opinion. But you really need to move all your fiash to a qt tank, or in your case with 21 fish maybe like 3 qt tanks. if it is more than your tang with ich then it is a problem i find.

Your skimmer is extremely small for a tank like that.

I have a 300 gph skimmer for my 120gallon tank. plus 30 gallon sump. and i have 4 fish in that tank, and its fully stocked

You have a 120 gallon skimmer for your 90 gallon + 100 gallon sump.
so treat your tank like its a 190 which means your skimmer is half as powerful as it needs to be.

 

A skimmer should be able to turn the tank over at the same rate as your overflow system- anything else is a waste of time.

If you have a 100 gal. tank then you need to flow 500 to 1000 gallons per hr. that is to say- your over flow should flow 5 to 10 times your tank and sumps total water volume in 1 hours time.

this means that your skimmer, and return pump, should flow/process the same gallons per hr. mind you, your return pump might have to be larger then your skimmer pump(s) due to head pressure loss.

 

Um that sounds a bit much. So for example you are saying that if someone had a small ten gallon tank a 65-100 gallon skimmer is needed, or for my 120 gallon tank i would need a skimmer rated for 600 to 1200 gph.

I am certainly no expert but have read quite a bit and talked with many people about this and the general consensus was for a skimmer to be about 1-2x your tank size. sorry i havent heard about having your skimmer 10x turnover. Just flow rate.

 

Ask yourself, if your skimmer is in your dirty sump's water, which is the purpose of the sump- to collect waste, do you not want to process as much of this water as possible so that it does not get returned back into your display tank?

Most skimmers are vastly over rated- I spoke with the owner of AETech about skimmers at some length - this company is the inventor of the downdraft skimmer BTW, and I learned quite a bit. A skimmer is not only used for waste removal but for oxengenation of your return water as well.

If your skimmer is under rated try this experiment- using an air pump place an air stone in your sump (away from your return pump) for a few days, watch what happens to all your critters- including your coral- you might be very suprized how nice they look. Why? O2 content in the overall water volume.

Your above statement is correct- if that is all the over flow you have- overflow, skimmer, and return pumps need to match. However, water turnover rate should be between 5 to 10 times your systems volume of water.

 

I would say that you should be okay with the fish you have since they are all pretty small, but I wouldnt add anymore to replace the ones you lost. How often were you doing water changes before this happened? If so how long since your last water change? Are there bio balls in your wet dry? With no prefilter they will become nitrate factories. Is it a 100 gallon wetdry? Or just rated for a 100 gallons? What brand of Protein skimmer do you have? We need to know those things too, to give you real advice...... IMHO

 

That is an interesting concept on skimmer size and quite different from what reef octopus told me. They said for my dnwb-110 which is an external skimmer I only want to turn the tank over 2x to 3x a day. They also said that to fast a turn over would cut down on the effectiveness due to loss in contact time. I am confused. What you are saying does make since though I am not sure I agree. Like everything else "back to research".

 

2-3x a day seems small. Cuz if my system is 150 gallons. And im turning it over 3 x that's like 450 gpd. I would need a skimmer rated at 20 gph for my 120 gallon tank. I was told 1-2x your tank volume per hour depending on your stock. Am I wrong in this interpretation of your question.